From 9145cd66ec3a5db8f0eb8f70242ea6a1a0d31d9f Mon Sep 17 00:00:00 2001
From: playX <adel.prokurov@gmail.com>
Date: Sun, 3 Oct 2021 10:08:21 +0300
Subject: [PATCH] js: add more tests to builtin/js and implement more builtin
 functions (#12049)

---
 vlib/builtin/js/array.js.v       |   9 +-
 vlib/builtin/js/byte.js.v        |  16 +
 vlib/builtin/js/int.js.v         | 100 ++++
 vlib/builtin/js/int_test.js.v    | 244 ++++++++
 vlib/builtin/js/map.js.v         |   2 +
 vlib/builtin/js/map_test.js.v    | 949 +++++++++++++++++++++++++++++++
 vlib/builtin/js/string.js.v      | 160 +++++-
 vlib/builtin/js/string_test.js.v | 897 +++++++++++++++++++++++++++++
 vlib/v/gen/js/infix.v            |   6 +-
 vlib/v/gen/js/js.v               |  19 +-
 10 files changed, 2384 insertions(+), 18 deletions(-)
 create mode 100644 vlib/builtin/js/int_test.js.v
 create mode 100644 vlib/builtin/js/map_test.js.v
 create mode 100644 vlib/builtin/js/string_test.js.v

diff --git a/vlib/builtin/js/array.js.v b/vlib/builtin/js/array.js.v
index f9124bdaf0..834ae617d3 100644
--- a/vlib/builtin/js/array.js.v
+++ b/vlib/builtin/js/array.js.v
@@ -194,13 +194,6 @@ pub fn (mut a array) insert_many(i int, val voidptr, size int) {
 	#a.val.arr.arr.splice(i,0,...val.arr.slice(0,+size))
 }
 
-pub fn (mut a array) join(separator string) string {
-	mut res := ''
-	#res = new string(a.val.arr.arr.join(separator +''));
-
-	return res
-}
-
 fn (mut a array) push(val voidptr) {
 	#a.val.arr.make_copy()
 	#if (arguments[2] && arguments[2].valueOf()) {a.val.arr.arr.push(...val)} else {
@@ -246,7 +239,7 @@ struct array_iterator {
 #}
 #array_iterator.prototype[Symbol.iterator] = function () { return this; }
 
-#array.prototype[Symbol.iterator] = function () { console.log(this.arr.index_start); return new array_iterator({ix: new int(0),end: new int(this.arr.len),arr: this}); }
+#array.prototype[Symbol.iterator] = function () { return new array_iterator({ix: new int(0),end: new int(this.arr.len),arr: this}); }
 #array.prototype.entries = function () { let result = []; for (let key = this.arr.index_start.val;key < this.arr.len.val;key++) { result.push([new int(key), this.arr.get(new int(key))]); } return result[Symbol.iterator](); }
 #array.prototype.map = function(callback) { return v_map(this,callback); }
 #array.prototype.filter = function(callback) { return v_filter(this,callback); }
diff --git a/vlib/builtin/js/byte.js.v b/vlib/builtin/js/byte.js.v
index 4a46e7852f..78b3f6fb2e 100644
--- a/vlib/builtin/js/byte.js.v
+++ b/vlib/builtin/js/byte.js.v
@@ -21,3 +21,19 @@ pub fn (c byte) str() string {
 
 	return res
 }
+
+pub fn (c byte) ascii_str() string {
+	res := ''
+	#res.str = String.fromCharCode(c.val)
+
+	return res
+}
+
+pub fn (c byte) repeat(count int) string {
+	mut res := ''
+	for _ in 0 .. count {
+		res += c.ascii_str()
+	}
+
+	return res
+}
diff --git a/vlib/builtin/js/int.js.v b/vlib/builtin/js/int.js.v
index 1220fb5033..dd67017078 100644
--- a/vlib/builtin/js/int.js.v
+++ b/vlib/builtin/js/int.js.v
@@ -1,5 +1,26 @@
 module builtin
 
+pub fn (i i8) str() string {
+	mut res := ''
+	#res.str = i.val.toString()
+
+	return res
+}
+
+pub fn (i i16) str() string {
+	mut res := ''
+	#res.str = i.val.toString()
+
+	return res
+}
+
+pub fn (i u16) str() string {
+	mut res := ''
+	#res.str = i.val.toString()
+
+	return res
+}
+
 pub fn (i int) str() string {
 	mut res := ''
 	#res = new string( i )
@@ -48,3 +69,82 @@ pub fn (i int_literal) str() string {
 
 	return res
 }
+
+pub fn (x u64) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x i64) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x u32) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x u16) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x i8) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x i16) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x int) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x int_literal) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+pub fn (x byte) hex() string {
+	res := ''
+	#res.str = x.val.toString(16)
+
+	return res
+}
+
+// hex returns a string with the hexadecimal representation
+// of the byte elements of the array.
+pub fn (b []byte) hex() string {
+	mut hex := ''
+	for i in b {
+		mut z := i
+		z = z
+		#let n0 = i.val >> 4
+		#hex.str += n0 < 10 ? String.fromCharCode(n0) : String.fromCharCode(n0 + 87)
+
+		#let n1 = i.val & 0xF
+		#hex.str += n1 < 10 ? String.fromCharCode(n1) : String.fromCharCode(n1 + 87)
+	}
+	return hex
+}
diff --git a/vlib/builtin/js/int_test.js.v b/vlib/builtin/js/int_test.js.v
new file mode 100644
index 0000000000..f760d463f6
--- /dev/null
+++ b/vlib/builtin/js/int_test.js.v
@@ -0,0 +1,244 @@
+const (
+	a = 3
+	u = u64(1)
+)
+
+fn test_const() {
+	b := (true && true) || false
+	assert b == true
+	assert a == 3
+	assert u == u64(1)
+	assert u == 1 // make sure this works without the cast
+}
+
+fn test_str_methods() {
+	assert i8(1).str() == '1'
+	assert i8(-1).str() == '-1'
+	assert i16(1).str() == '1'
+	assert i16(-1).str() == '-1'
+	assert int(1).str() == '1'
+	assert int(-1).str() == '-1'
+	assert int(2147483647).str() == '2147483647'
+	// todo: overflow check for integers
+	// assert int(2147483648).str() == '-2147483648'
+	// assert int(-2147483648).str() == '-2147483648'
+	assert i64(1).str() == '1'
+	assert i64(-1).str() == '-1'
+	assert u16(1).str() == '1'
+	// assert u16(-1).str() == '65535'
+	assert u32(1).str() == '1'
+	// assert u32(-1).str() == '4294967295'
+	assert u64(1).str() == '1'
+	// assert u64(-1).str() == '18446744073709551615'
+}
+
+fn test_and_precendence() {
+	assert (2 & 0 == 0) == ((2 & 0) == 0)
+	assert (2 & 0 != 0) == ((2 & 0) != 0)
+	assert (0 & 0 >= 0) == ((0 & 0) >= 0)
+	assert (0 & 0 <= 0) == ((0 & 0) <= 0)
+	assert (0 & 0 < 1) == ((0 & 0) < 1)
+	assert (1 & 2 > 0) == ((1 & 2) > 0)
+}
+
+fn test_or_precendence() {
+	assert (1 | 0 == 0) == ((1 | 0) == 0)
+	assert (1 | 0 != 1) == ((1 | 0) != 1)
+	assert (1 | 0 >= 2) == ((1 | 0) >= 2)
+	assert (1 | 0 <= 0) == ((1 | 0) <= 0)
+	assert (1 | 0 < 0) == ((1 | 0) < 0)
+	assert (1 | 0 > 1) == ((1 | 0) > 1)
+}
+
+fn test_xor_precendence() {
+	assert (1 ^ 0 == 2) == ((1 ^ 0) == 2)
+	assert (1 ^ 0 != 2) == ((1 ^ 0) != 2)
+	assert (1 ^ 0 >= 0) == ((1 ^ 0) >= 0)
+	assert (1 ^ 0 <= 1) == ((1 ^ 0) <= 1)
+	assert (1 ^ 0 < 0) == ((1 ^ 0) < 0)
+	assert (1 ^ 0 > 1) == ((1 ^ 0) > 1)
+}
+
+fn test_left_shift_precendence() {
+	assert (2 << 4 | 3) == ((2 << 4) | 3)
+	assert (2 << 4 | 3) != (2 << (4 | 3))
+}
+
+fn test_right_shift_precendence() {
+	assert (256 >> 4 | 3) == ((256 >> 4) | 3)
+	assert (256 >> 4 | 3) != (256 >> (4 | 3))
+}
+
+fn test_i8_print() {
+	b := i8(0)
+	println(b)
+	c := i16(7)
+	println(c)
+	d := u16(6)
+	println(d)
+	assert true
+}
+
+/*
+fn test_cmp() {
+	assert 1 ≠ 2
+	assert 1 ⩽ 2
+	assert 1 ⩾ 0
+}
+*/
+type MyInt = int
+
+fn test_int_alias() {
+	i := MyInt(2)
+	assert i + 10 == 12
+}
+
+fn test_hex() {
+	x := u64(10)
+	assert x.hex() == 'a'
+	b := 1234
+	assert b.hex() == '4d2'
+	b1 := -1
+	// assert b1.hex() == 'ffffffff'
+	// unsigned tests
+	// assert u8(12).hex() == '0c'
+	// assert u8(255).hex() == 'ff'
+	assert u16(65535).hex() == 'ffff'
+	// assert u32(-1).hex() == 'ffffffff'
+	// assert u64(-1).hex() == 'ffffffffffffffff'
+	// signed tests
+	// assert i8(-1).hex() == 'ff'
+	assert i8(12).hex() == 'c'
+	assert i16(32767).hex() == '7fff'
+	assert int(2147483647).hex() == '7fffffff'
+	assert i64(9223372036854775807).hex() == '7fffffffffffffff'
+}
+
+fn test_bin() {
+	x1 := 0b10
+	assert x1 == 2
+	x2 := 0b10101010
+	assert x2 == 0xAA
+	x3 := -0b0000001
+	assert x3 == -1
+	x4 := 0b11111111
+	assert x4 == 255
+	x5 := byte(0b11111111)
+	assert x5 == 255
+	x6 := char(0b11111111)
+	assert int(x6) == -1
+	x7 := 0b0
+	assert x7 == 0
+	x8 := -0b0
+	assert x8 == 0
+}
+
+fn test_oct() {
+	x1 := 0o12
+	assert x1 == 10
+	x2 := 0o350
+	assert x2 == 232
+	x3 := 0o00073
+	assert x3 == 59
+	x4 := 0
+	assert x4 == 0
+	x5 := 195
+	assert x5 == 195
+	x6 := -0o744
+	assert x6 == -484
+	x7 := -0o000042
+	assert x7 == -34
+	x8 := -112
+	assert x8 == -112
+	x9 := -0
+	assert x9 == 0
+}
+
+fn test_num_separator() {
+	// int
+	assert 100_000_0 == 1000000
+	assert -2_23_4_6 == -22346
+
+	// bin
+	assert 0b0_11 == 3
+	assert -0b0_100 == -4
+
+	// oct
+	assert 0o1_73 == 123
+	assert -0o17_5 == -125
+	assert -0o175 == -125
+
+	// hex
+	assert 0xFF == 255
+	assert 0xF_F == 255
+
+	// f32 or f64
+	assert 312_2.55 == 3122.55
+	assert 312_2.55 == 3122.55
+}
+
+fn test_int_decl() {
+	x1 := 0
+	x2 := 1333
+	x3 := -88955
+	x4 := 2000000000
+	x5 := -1999999999
+	assert typeof(x1).name == 'int'
+	assert typeof(x2).name == 'int'
+	assert typeof(x3).name == 'int'
+	assert typeof(x4).name == 'int'
+	assert typeof(x5).name == 'int'
+	x7 := u64(-321314588900011)
+	assert typeof(x7).name == 'u64'
+}
+
+fn test_int_to_hex() {
+	// array hex
+	/*
+	st := [byte(`V`), `L`, `A`, `N`, `G`]
+	assert st.hex() == '564c414e47'
+	assert st.hex().len == 10
+	st1 := [byte(0x41)].repeat(100)
+	assert st1.hex() == '41'.repeat(100)*/
+	// --- int to hex tests
+	c0 := 12
+	// 8Bit
+	assert byte(0).hex() == '0'
+	assert byte(c0).hex() == 'c'
+	assert i8(c0).hex() == 'c'
+	assert byte(127).hex() == '7f'
+	assert i8(127).hex() == '7f'
+	assert byte(255).hex() == 'ff'
+	// assert byte(-1).hex() == 'ff'
+	// 16bit
+	assert u16(0).hex() == '0'
+	assert i16(c0).hex() == 'c'
+	assert u16(c0).hex() == 'c'
+	assert i16(32767).hex() == '7fff'
+	assert u16(32767).hex() == '7fff'
+	// assert i16(-1).hex() == 'ffff'
+	assert u16(65535).hex() == 'ffff'
+	// 32bit
+	assert u32(0).hex() == '0'
+	assert c0.hex() == 'c'
+	assert u32(c0).hex() == 'c'
+	assert 2147483647.hex() == '7fffffff'
+	assert u32(2147483647).hex() == '7fffffff'
+	// assert (-1).hex() == 'ffffffffffffffff'
+	assert u32(4294967295).hex() == 'ffffffff'
+	// 64 bit
+	assert u64(0).hex() == '0'
+	assert i64(c0).hex() == 'c'
+	assert u64(c0).hex() == 'c'
+	assert i64(9223372036854775807).hex() == '7fffffffffffffff'
+	assert u64(9223372036854775807).hex() == '7fffffffffffffff'
+	// assert i64(-1).hex() == 'ffffffffffffffff'
+	assert u64(18446744073709551615).hex() == 'ffffffffffffffff'
+}
+
+fn test_repeat() {
+	b := byte(`V`)
+	assert b.repeat(5) == 'VVVVV'
+	assert b.repeat(1) == b.ascii_str()
+	assert b.repeat(0) == ''
+}
diff --git a/vlib/builtin/js/map.js.v b/vlib/builtin/js/map.js.v
index 1b913674b6..5bcd65fb55 100644
--- a/vlib/builtin/js/map.js.v
+++ b/vlib/builtin/js/map.js.v
@@ -25,3 +25,5 @@ pub fn (m &map) free() {}
 #res += '}'
 #return res;
 #}
+
+#map.prototype.getOrSet = function (key, init) { if (this.map.has(key)) { return this.map.get(key); } else { this.map.set(key,init); return init; } }
diff --git a/vlib/builtin/js/map_test.js.v b/vlib/builtin/js/map_test.js.v
new file mode 100644
index 0000000000..76b79ed47b
--- /dev/null
+++ b/vlib/builtin/js/map_test.js.v
@@ -0,0 +1,949 @@
+import rand
+
+const (
+	strings = unique_strings(200, 10)
+)
+
+fn unique_strings(arr_len int, str_len int) []string {
+	mut arr := []string{cap: arr_len}
+	for arr.len < arr_len {
+		str := rand.string(str_len)
+		if str !in arr {
+			arr << str
+		}
+	}
+	return arr
+}
+
+fn test_get_and_set_many() {
+	mut m := map[string]int{}
+	for i, s in strings {
+		m[s] = i
+		assert m[s] == i
+		assert m.len == i + 1
+	}
+	for i, s in strings {
+		assert m[s] == i
+	}
+	assert m.len == strings.len
+}
+
+fn test_for_in_many() {
+	mut m := map[string]int{}
+	for i, s in strings {
+		m[s] = i
+	}
+	for k, v in m {
+		assert m[k] == v
+	}
+}
+
+fn test_keys_many() {
+	mut m := map[string]int{}
+	for i, s in strings {
+		m[s] = i
+	}
+	keys := m.keys()
+	assert keys.len == strings.len
+	assert keys.len == m.len
+	assert keys == strings
+}
+
+fn test_deletes_many() {
+	mut m := map[string]int{}
+	for i, s in strings {
+		m[s] = i
+	}
+	for i, s in strings {
+		m.delete(s)
+		assert m[s] == 0
+		assert m.len == strings.len - (i + 1)
+	}
+	assert m.len == 0
+	assert m.keys().len == 0
+}
+
+struct User {
+mut:
+	name string
+}
+
+struct Aaa {
+mut:
+	m     map[string]int
+	users map[string]User
+}
+
+fn (mut a Aaa) set(key string, val int) {
+	a.m[key] = val
+}
+
+fn test_map() {
+	mut m := map[string]int{}
+	assert m.len == 0
+	m['hi'] = 80
+	m['hello'] = 101
+	assert m['hi'] == 80
+	assert m['hello'] == 101
+	assert m.len == 2
+	assert 'hi' in m
+	mut sum := 0
+	// Test `for in`
+	for _, val in m {
+		sum += val
+	}
+	assert sum == 80 + 101
+	// Test `.keys()`
+	keys := m.keys()
+	assert keys.len == 2
+	assert 'hi' in keys
+	assert 'hello' in keys
+	m.delete('hi')
+	assert m.len == 1
+	m.delete('aloha')
+	assert m.len == 1
+	assert m['hi'] == 0
+	assert m.keys().len == 1
+	assert m.keys()[0] == 'hello'
+	// //
+	mut users := map[string]User{}
+	users['1'] = User{'Peter'}
+	peter := users['1']
+	assert peter.name == 'Peter'
+	mut a := Aaa{
+		m: map[string]int{}
+		users: map[string]User{}
+	}
+	a.users['Bob'] = User{'Bob'}
+	q := a.users['Bob']
+	assert q.name == 'Bob'
+	// test struct field change
+	a.users['Bob'].name = 'bob'
+	q2 := a.users['Bob']
+	assert q2.name == 'bob'
+	a.m['one'] = 1
+	a.set('two', 2)
+	assert a.m['one'] == 1
+	assert a.m['two'] == 2
+}
+
+fn test_map_init() {
+	one := 'one'
+	three := 'three'
+	m := {
+		one:   1
+		'two': 2
+		three: 1 + 2
+	}
+	assert m['one'] == 1
+	assert m['two'] == 2
+	assert m['three'] == 3
+	assert m['unknown'] == 0
+}
+
+fn test_string_map() {
+	// m := map[string]Fn
+}
+
+fn test_large_map() {
+	// ticks := time.ticks()
+	mut nums := map[string]int{}
+	n := 30 * 1000
+	for i in 0 .. n {
+		key := i.str()
+		nums[key] = i
+	}
+	assert nums['1'] == 1
+	assert nums['999'] == 999
+	assert nums['1000000'] == 0
+	// println(time.ticks() - ticks)
+}
+
+fn test_various_map_value() {
+	mut m1 := map[string]int{}
+	m1['test'] = 1
+	assert m1['test'] == 1
+	mut m2 := map[string]string{}
+	m2['test'] = 'test'
+	assert m2['test'] == 'test'
+	mut m3 := map[string]i8{}
+	m3['test'] = i8(0)
+	assert m3['test'] == i8(0)
+	mut m4 := map[string]i16{}
+	m4['test'] = i16(0)
+	assert m4['test'] == i16(0)
+	mut m7 := map[string]u16{}
+	m7['test'] = u16(0)
+	assert m7['test'] == u16(0)
+	mut m8 := map[string]u32{}
+	m8['test'] = u32(0)
+	assert m8['test'] == u32(0)
+	mut m9 := map[string]bool{}
+	m9['test'] = true
+	assert m9['test'] == true
+	mut m10 := map[string]byte{}
+	m10['test'] = byte(0)
+	assert m10['test'] == byte(0)
+	mut m11 := map[string]f32{}
+	m11['test'] = f32(0.0)
+	assert m11['test'] == f32(0.0)
+	mut m12 := map[string]f64{}
+	m12['test'] = f64(0.0)
+	assert m12['test'] == f64(0.0)
+	// mut m13 := map[string]rune
+	// m13['test'] = rune(0)
+	// assert m13['test'] == rune(0)
+	// todo(playX): pointer equality does not work yet
+	/*
+	mut m14 := map[string]voidptr{}
+	m14['test'] = voidptr(0)
+	assert m14['test'] == voidptr(0)
+	mut m15 := map[string]&byte{}
+	m15['test'] = &byte(0)
+	assert m15['test'] == &byte(0)
+	mut m16 := map[string]i64{}
+	m16['test'] = i64(0)
+	assert m16['test'] == i64(0)
+	mut m17 := map[string]u64{}
+	m17['test'] = u64(0)
+	assert m17['test'] == u64(0)
+	mut m18 := map[string]&int{}
+	m18['test'] = &int(0)
+	assert m18['test'] == &int(0)*/
+}
+
+fn test_string_arr() {
+	mut m := map[string][]string{}
+	m['a'] = ['one', 'two']
+	assert m['a'].len == 2
+	assert m['a'][0] == 'one'
+	assert m['a'][1] == 'two'
+}
+
+fn mut_map(mut m map[string]int) {
+	m['a'] = 10
+}
+
+fn test_mut_arg() {
+	mut m := map[string]int{}
+	mut_map(mut m)
+	a := m['a']
+	assert a == 10
+}
+
+fn test_delete() {
+	mut m := map[string]int{}
+	m['one'] = 1
+	m['two'] = 2
+	println(m['two']) // => "2"
+	m.delete('two')
+	println(m['two'].str()) // => 0
+	assert ('two' in m) == false
+	println('two' in m) // => true, on Linux  and Windows  <-- wrong !
+}
+
+fn test_delete_size() {
+	arr := ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
+	mut m := map[string]int{}
+	for _ in 0 .. 10 {
+		for i in 0 .. 10 {
+			m[arr[i]] = i
+		}
+		assert m.len == 10
+		println(m.len)
+		for i in 0 .. 10 {
+			m.delete(arr[i])
+		}
+	}
+}
+
+fn test_nested_for_in() {
+	mut m := map[string]int{}
+	for i in 0 .. 1000 {
+		m[i.str()] = i
+	}
+	mut i := 0
+	for key1, _ in m {
+		assert key1 == i.str()
+		i++
+		mut j := 0
+		for key2, _ in m {
+			assert key2 == j.str()
+			j++
+		}
+	}
+}
+
+fn test_delete_in_for_in() {
+	mut m := map[string]string{}
+	for i in 0 .. 1000 {
+		m[i.str()] = i.str()
+	}
+	mut i := 0
+	for key, _ in m {
+		assert key == i.str()
+		m.delete(key)
+		i++
+	}
+	assert m.str() == '{}'
+	assert m.len == 0
+}
+
+fn test_set_in_for_in() {
+	mut m := map[string]string{}
+	for i in 0 .. 10 {
+		m[i.str()] = i.str()
+	}
+	mut last_key := ''
+	mut i := 0
+	for key, _ in m {
+		m['10'] = '10'
+		assert key == i.str()
+		last_key = key
+		i++
+	}
+	assert last_key == '10'
+}
+
+fn test_delete_and_set_in_for_in() {
+	mut m := map[string]string{}
+	for i in 0 .. 1000 {
+		m[i.str()] = i.str()
+	}
+	mut i := 0
+	for key, _ in m {
+		assert key == i.str()
+		m.delete(key)
+		m[key] = i.str()
+		if i == 999 {
+			break
+		}
+		i++
+	}
+	assert m.len == 1000
+	i = 0
+	for key, _ in m {
+		assert m[key] == i.str()
+		i++
+	}
+	assert i == 1000
+}
+
+struct Mstruct1 {
+pub mut:
+	mymap map[string]int
+}
+
+struct Mstruct2 {
+pub mut:
+	mymap map[string]f64
+}
+
+struct Mstruct3 {
+pub mut:
+	mymap map[string]u16
+}
+
+fn test_map_assign() {
+	mut a := map[string]f64{}
+	mut b := map[string]int{}
+	mut c := map[string]u16{}
+	a = {
+		'x': 12.4
+		'y': 3
+	}
+	b = {
+		'u': -13
+		'v': 12
+	}
+	c = {
+		's': u16(5)
+		't': 3
+	}
+	_ := Mstruct1{{
+		'p': 12
+	}}
+	_ := Mstruct2{{
+		'q': 1.7
+	}}
+	_ := Mstruct3{{
+		'r': u16(6)
+		's': 5
+	}}
+}
+
+fn test_postfix_op_directly() {
+	mut a := map[string]int{}
+	a['aaa']++
+	assert a['aaa'] == 1
+	a['aaa']++
+	assert a['aaa'] == 2
+	a['bbb']--
+	assert a['bbb'] == -1
+	a['bbb']--
+	assert a['bbb'] == -2
+}
+
+fn test_map_push_directly() {
+	mut a := map[string][]string{}
+	a['aaa'] << ['a', 'b', 'c']
+	assert a['aaa'].len == 3
+	assert a['aaa'] == ['a', 'b', 'c']
+}
+
+fn test_assign_directly() {
+	mut a := map[string]int{}
+	a['aaa'] += 4
+	assert a['aaa'] == 4
+	a['aaa'] -= 2
+	assert a['aaa'] == 2
+}
+
+fn test_map_in_directly() {
+	for k, v in {
+		'aa': 1
+	} {
+		assert k == 'aa'
+		assert v == 1
+	}
+}
+
+fn test_plus_assign_string() {
+	mut m := {
+		'one': ''
+	}
+	m['one'] += '1'
+	assert m.len == 1
+	assert m['one'] == '1'
+}
+
+fn test_map_keys_to_array() {
+	m := {
+		'a': 'b'
+		'c': 'd'
+	}
+	mut arr := []string{}
+	for k, _ in m {
+		arr << k
+	}
+	sarr := arr.str()
+	println(sarr)
+	assert sarr == "['a', 'c']"
+}
+
+fn map_in_mut(mut m map[string]int) {
+	if 'one' in m {
+		m['one'] = 2
+	}
+}
+
+fn test_map_in_mut() {
+	mut m := {
+		'one': 1
+	}
+	map_in_mut(mut m)
+	assert m['one'] == 2
+}
+
+fn test_map_in() {
+	m := {
+		'Foo': 'bar'
+	}
+	if 'foo'.capitalize() in m {
+		println('ok')
+	} else {
+		assert false
+	}
+}
+
+fn mut_map_with_relation_op_in_fn(mut m map[string]int) {
+	if m['one'] == 1 {
+		m['three'] = 3
+	}
+	if m['two'] != 1 {
+		m['four'] = 4
+	}
+	if m['one'] > 0 {
+		m['five'] = 5
+	}
+	if m['one'] < 2 {
+		m['six'] = 6
+	}
+	if m['two'] >= 2 {
+		m['seven'] = 7
+	}
+	if m['two'] <= 2 {
+		m['eight'] = 8
+	}
+}
+
+fn test_mut_map_with_relation_op_in_fn() {
+	mut m := {
+		'one': 1
+		'two': 2
+	}
+	mut_map_with_relation_op_in_fn(mut m)
+	assert 'three' in m
+	assert 'four' in m
+	assert 'five' in m
+	assert 'six' in m
+	assert 'seven' in m
+	assert 'eight' in m
+}
+
+fn test_map_str_after_delete() {
+	mut m := {
+		'first':  1
+		'second': 2
+		'third':  3
+	}
+	osm := '$m'
+	m.delete('second')
+	nsm := '$m'
+	println('m: $m')
+	assert osm == "{'first': 1, 'second': 2, 'third': 3}"
+	assert nsm == "{'first': 1, 'third': 3}"
+}
+
+fn test_modify_map_value() {
+	mut m1 := {
+		'foo': 3
+		'bar': -7
+	}
+	m1['foo'] += 5
+	m1['bar'] *= -2
+	assert m1['foo'] == 8
+	assert m1['bar'] == 14
+}
+
+fn test_map_clone() {
+	mut nums := {
+		'foo': 1
+		'bar': 2
+	}
+	mut nums2 := nums.clone()
+	nums2['foo']++
+	nums2['bar'] *= 4
+	assert nums['foo'] == 1
+	assert nums['bar'] == 2
+	assert nums2['foo'] == 2
+	assert nums2['bar'] == 8
+}
+
+struct MValue {
+	name string
+	misc map[string]string
+}
+
+fn test_map_default_zero() {
+	m := map[string]MValue{}
+	v := m['unknown']
+	x := v.misc['x']
+	println(x)
+	assert x == ''
+}
+
+fn test_map_or() {
+	m := {
+		'first':  1
+		'second': 2
+		'third':  3
+	}
+	_ = m
+	// num := m['first'] or { return }
+}
+
+fn test_int_keys() {
+	mut m := map[int]int{}
+	m[3] = 9
+	m[4] = 16
+	assert m.len == 2
+	assert m[3] == 9
+	assert m[4] == 16
+	m[5] += 24
+	m[5]++
+	assert m[5] == 25
+	mut m2 := {
+		3: 9
+		4: 16
+		5: 25
+	}
+
+	four := 4
+	m2.delete(3)
+	m2.delete(four)
+	m2.delete(5)
+	assert m2.len == 0
+	assert m2[3] == 0
+	assert m2[4] == 0
+	assert m2[5] == 0
+	assert m2.keys() == []
+
+	m2 = {
+		3: 9
+		4: 16
+		5: 25
+	}
+
+	assert m2.len == 3
+	// clone
+	mc := m.clone()
+	same := mc == m
+	assert same
+	assert mc.len == 3
+	assert mc.keys() == [3, 4, 5]
+	mut all := []int{}
+	for k, v in mc {
+		assert m[k] == v
+		all << k
+		all << v
+	}
+	assert all == [3, 9, 4, 16, 5, 25]
+
+	mut m3 := {
+		1: 'one'
+		2: 'two'
+	}
+	assert m3[1] == 'one'
+	m3.delete(1)
+}
+
+enum Color {
+	red
+	green
+	blue
+}
+
+type ColorAlias = Color
+
+fn test_alias_enum() {
+	mut m := map[ColorAlias]string{}
+	m[Color.red] = 'hi'
+	assert m[Color.red] == 'hi'
+}
+
+fn test_enum_in_map() {
+	mut m := map[Color]string{}
+	m[Color.red] = 'hi'
+	assert Color.red in m
+	assert Color.green !in m
+	assert Color.blue !in m
+}
+
+fn test_voidptr_keys() {
+	mut m := map[voidptr]string{}
+	v := 5
+	m[&v] = 'var'
+	m[&m] = 'map'
+	assert m[&v] == 'var'
+	assert m[&m] == 'map'
+	assert m.len == 2
+}
+
+fn test_rune_keys() {
+	mut m := {
+		`!`: 2
+		`%`: 3
+	}
+	assert typeof(m).name == 'map[rune]int'
+	assert m[`!`] == 2
+	m[`@`] = 7
+	assert m.len == 3
+	println(m)
+	assert '$m' == '{`!`: 2, `%`: 3, `@`: 7}'
+
+	mut a := []rune{}
+	for k, v in m {
+		a << k
+		a << rune(v) + `0`
+	}
+	assert a == [`!`, `2`, `%`, `3`, `@`, `7`]
+}
+
+fn test_eq() {
+	a := {
+		'a': 1
+		'b': 2
+	}
+	assert a == {
+		'a': 1
+		'b': 2
+	}
+	b := {
+		'a': [[1]]
+		'b': [[2]]
+	}
+	assert b == {
+		'a': [[1]]
+		'b': [[2]]
+	}
+	c := {
+		'a': {
+			'11': 1
+		}
+		'b': {
+			'22': 2
+		}
+	}
+	assert c == {
+		'a': {
+			'11': 1
+		}
+		'b': {
+			'22': 2
+		}
+	}
+	d := {
+		'a': MValue{
+			name: 'aa'
+			misc: {
+				'11': '1'
+			}
+		}
+		'b': MValue{
+			name: 'bb'
+			misc: {
+				'22': '2'
+			}
+		}
+	}
+	assert d == {
+		'a': MValue{
+			name: 'aa'
+			misc: {
+				'11': '1'
+			}
+		}
+		'b': MValue{
+			name: 'bb'
+			misc: {
+				'22': '2'
+			}
+		}
+	}
+}
+
+fn test_non_string_key_map_str() {
+	assert {
+		23: 4
+	}.str() == '{23: 4}'
+	assert {
+		`a`: 12
+		`b`: 13
+	}.str() == '{`a`: 12, `b`: 13}'
+	assert {
+		23: 'foo'
+		25: 'bar'
+	}.str() == "{23: 'foo', 25: 'bar'}"
+}
+
+fn test_map_assign_empty_map_init() {
+	mut a := {
+		'one': 1
+	}
+	a = {}
+	println(a)
+	assert a == map[string]int{}
+	assert '$a' == '{}'
+}
+
+fn test_in_map_literal() {
+	assert 1 in {
+		1: 'one'
+	}
+}
+
+fn test_byte_keys() {
+	mut m := map[byte]byte{}
+	byte_max := byte(255)
+	for i in byte(0) .. byte_max {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in byte(0) .. 100 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == byte_max
+	keys := m.keys()
+	for i in byte(0) .. byte_max {
+		assert keys[i] == i
+	}
+	for i in byte(0) .. byte_max {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_i16_keys() {
+	mut m := map[i16]i16{}
+	end := i16(1000)
+	for i in i16(0) .. end {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in i16(0) .. 500 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == end
+	keys := m.keys()
+	for i in i16(0) .. end {
+		assert keys[i] == i
+	}
+	for i in i16(0) .. end {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_u16_keys() {
+	mut m := map[u16]u16{}
+	end := u16(1000)
+	for i in u16(0) .. end {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in u16(0) .. 500 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == end
+	keys := m.keys()
+	for i in u16(0) .. end {
+		assert keys[i] == i
+	}
+	for i in u16(0) .. end {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_u32_keys() {
+	mut m := map[u32]u32{}
+	end := u32(1000)
+	for i in u32(0) .. end {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in u32(0) .. 500 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == end
+	keys := m.keys()
+	for i in u32(0) .. end {
+		assert keys[i] == i
+	}
+	for i in u32(0) .. end {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_int_keys2() {
+	mut m := map[int]int{}
+	end := 1000
+	for i in int(0) .. end {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in int(0) .. 500 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == end
+	keys := m.keys()
+	for i in int(0) .. end {
+		assert keys[i] == i
+	}
+	for i in int(0) .. end {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_i64_keys() {
+	mut m := map[i64]i64{}
+	end := i64(1000)
+	for i in i64(0) .. end {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in i64(0) .. 500 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == end
+	keys := m.keys()
+	for i in i64(0) .. end {
+		assert keys[i] == i
+	}
+	for i in i64(0) .. end {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_u64_keys() {
+	mut m := map[u64]u64{}
+	end := u64(1000)
+	for i in u64(0) .. end {
+		m[i] = i
+		assert m[i] == i
+	}
+	for k, v in m {
+		assert k == v
+	}
+	for i in u64(0) .. 500 {
+		m[i]++
+		assert m[i] == i + 1
+	}
+	assert m.len == end
+	keys := m.keys()
+	for i in u64(0) .. end {
+		assert keys[i] == i
+	}
+	for i in u64(0) .. end {
+		m.delete(i)
+		assert m[i] == 0
+	}
+	assert m.len == 0
+}
+
+fn test_map_set_fixed_array_variable() {
+	mut m := map[string][2]f64{}
+	m['A'] = [1.1, 2.2]!
+	println(m)
+	assert '$m' == "{'A': [1.1, 2.2]}"
+
+	mut m2 := map[string][2]f64{}
+	arr := [1.1, 2.2]!
+	m2['A'] = arr
+	println(m2)
+	assert '$m2' == "{'A': [1.1, 2.2]}"
+}
diff --git a/vlib/builtin/js/string.js.v b/vlib/builtin/js/string.js.v
index d276435d61..1420f5cfee 100644
--- a/vlib/builtin/js/string.js.v
+++ b/vlib/builtin/js/string.js.v
@@ -10,6 +10,10 @@ pub fn (s string) slice(a int, b int) string {
 	return string(s.str.slice(a, b))
 }
 
+pub fn (s string) substr(start int, end int) string {
+	return s.slice(start, end)
+}
+
 pub fn (s string) after(dot string) string {
 	return string(s.str.slice(s.str.lastIndexOf(dot.str) + 1, int(s.str.length)))
 }
@@ -20,20 +24,37 @@ pub fn (s string) after_char(dot byte) string {
 }
 
 pub fn (s string) all_after(dot string) string {
-	return string(s.str.slice(s.str.indexOf(dot.str) + 1, int(s.str.length)))
+	pos := if dot.len == 0 { -1 } else { s.str.indexOf(dot.str) }
+	if pos == -1 {
+		return s.clone()
+	}
+	return s[pos + dot.len..]
 }
 
 // why does this exist?
 pub fn (s string) all_after_last(dot string) string {
-	return s.after(dot)
+	pos := if dot.len == 0 { -1 } else { s.str.lastIndexOf(dot.str) }
+	if pos == -1 {
+		return s.clone()
+	}
+	return s[pos + dot.len..]
 }
 
 pub fn (s string) all_before(dot string) string {
-	return string(s.str.slice(0, s.str.indexOf(dot.str)))
+	pos := if dot.len == 0 { -1 } else { s.str.indexOf(dot.str) }
+	if pos == -1 {
+		return s.clone()
+	}
+	return s[..pos]
+	// return string(s.str.slice(0, s.str.indexOf(dot.str)))
 }
 
 pub fn (s string) all_before_last(dot string) string {
-	return string(s.str.slice(0, s.str.lastIndexOf(dot.str)))
+	pos := if dot.len == 0 { -1 } else { s.str.lastIndexOf(dot.str) }
+	if pos == -1 {
+		return s.clone()
+	}
+	return s[..pos]
 }
 
 pub fn (s string) bool() bool {
@@ -79,6 +100,9 @@ pub fn (s string) contains_any(chars string) bool {
 }
 
 pub fn (s string) contains_any_substr(chars []string) bool {
+	if chars.len == 0 {
+		return true
+	}
 	for x in chars {
 		if s.str.includes(x.str) {
 			return true
@@ -726,3 +750,131 @@ pub fn (s string) replace_once(rep string, with_ string) string {
 
 	return s2
 }
+
+pub fn (s string) title() string {
+	words := s.split(' ')
+	mut tit := []string{}
+	for word in words {
+		tit << word.capitalize()
+	}
+
+	title := tit.join(' ')
+	return title
+}
+
+// index_any returns the position of any of the characters in the input string - if found.
+pub fn (s string) index_any(chars string) int {
+	for i, ss in s {
+		for c in chars {
+			if c == ss {
+				return i
+			}
+		}
+	}
+	return -1
+}
+
+/*
+// limit returns a portion of the string, starting at `0` and extending for a given number of characters afterward.
+// 'hello'.limit(2) => 'he'
+// 'hi'.limit(10) => 'hi'
+pub fn (s string) limit(max int) string {
+	u := s.runes()
+	if u.len <= max {
+		return s.clone()
+	}
+	return u[0..max].string()
+}
+*/
+// is_title returns true if all words of the string is capitalized.
+// Example: assert 'Hello V Developer'.is_title() == true
+pub fn (s string) is_title() bool {
+	words := s.split(' ')
+	for word in words {
+		if !word.is_capital() {
+			return false
+		}
+	}
+	return true
+}
+
+// is_capital returns `true` if the first character in the string is a capital letter.
+// Example: assert 'Hello'.is_capital() == true
+[direct_array_access]
+pub fn (s string) is_capital() bool {
+	if s.len == 0 || !(s[0] >= `A` && s[0] <= `Z`) {
+		return false
+	}
+	for i in 1 .. s.len {
+		if s[i] >= `A` && s[i] <= `Z` {
+			return false
+		}
+	}
+	return true
+}
+
+// is_upper returns `true` if all characters in the string is uppercase.
+// Example: assert 'HELLO V'.is_upper() == true
+pub fn (s string) is_upper() bool {
+	res := false
+	#res.val = s.str == s.str.toUpperCase() && s.str != s.str.toLowerCase()
+
+	return res
+}
+
+// is_upper returns `true` if all characters in the string is uppercase.
+// Example: assert 'HELLO V'.is_upper() == true
+pub fn (s string) is_lower() bool {
+	res := false
+	#res.val = s.str == s.str.toLowerCase() && s.str != s.str.toUpperCase()
+
+	return res
+}
+
+pub fn (s string) reverse() string {
+	res := ''
+	#res.str = [...s.str].reverse().join('')
+
+	return res
+}
+
+pub fn (s string) trim(cutset string) string {
+	if s.len < 1 || cutset.len < 1 {
+		return s.clone()
+	}
+	mut pos_left := 0
+	mut pos_right := s.len - 1
+	mut cs_match := true
+	for pos_left <= s.len && pos_right >= -1 && cs_match {
+		cs_match = false
+		for cs in cutset {
+			if s[pos_left] == cs {
+				pos_left++
+				cs_match = true
+				break
+			}
+		}
+		for cs in cutset {
+			if s[pos_right] == cs {
+				pos_right--
+				cs_match = true
+				break
+			}
+		}
+		if pos_left > pos_right {
+			return ''
+		}
+	}
+	return s.substr(pos_left, pos_right + 1)
+}
+
+pub fn (s []string) join(sep string) string {
+	mut res := ''
+	for i, str in s {
+		res += str
+		if i != s.len - 1 {
+			res += sep
+		}
+	}
+	return res
+}
diff --git a/vlib/builtin/js/string_test.js.v b/vlib/builtin/js/string_test.js.v
new file mode 100644
index 0000000000..21387f29d0
--- /dev/null
+++ b/vlib/builtin/js/string_test.js.v
@@ -0,0 +1,897 @@
+import strings
+
+// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+struct Foo {
+	bar int
+mut:
+	str string
+}
+
+fn test_add() {
+	mut a := 'a'
+	a += 'b'
+	assert a == ('ab')
+	a = 'a'
+	for i := 1; i < 1000; i++ {
+		a += 'b'
+	}
+	assert a.len == 1000
+	assert a.ends_with('bbbbb')
+	a += '123'
+	assert a.ends_with('3')
+}
+
+fn test_ends_with() {
+	a := 'browser.v'
+	assert a.ends_with('.v')
+
+	s := 'V Programming Language'
+	assert s.ends_with('guage') == true
+	assert s.ends_with('Language') == true
+	assert s.ends_with('Programming Language') == true
+	assert s.ends_with('V') == false
+}
+
+fn test_between() {
+	s := 'hello [man] how you doing'
+	assert s.find_between('[', ']') == 'man'
+}
+
+fn test_compare() {
+	a := 'Music'
+	b := 'src'
+	assert b >= a
+}
+
+fn test_lt() {
+	a := ''
+	b := 'a'
+	c := 'a'
+	d := 'b'
+	e := 'aa'
+	f := 'ab'
+	assert a < b
+	assert !(b < c)
+	assert c < d
+	assert !(d < e)
+	assert c < e
+	assert e < f
+}
+
+fn test_ge() {
+	a := 'aa'
+	b := 'aa'
+	c := 'ab'
+	d := 'abc'
+	e := 'aaa'
+	assert b >= a
+	assert c >= b
+	assert d >= c
+	assert !(c >= d)
+	assert e >= a
+}
+
+fn test_compare_strings() {
+	a := 'aa'
+	b := 'aa'
+	c := 'ab'
+	d := 'abc'
+	e := 'aaa'
+	assert compare_strings(a, b) == 0
+	assert compare_strings(b, c) == -1
+	assert compare_strings(c, d) == -1
+	assert compare_strings(d, e) == 1
+	assert compare_strings(a, e) == -1
+	assert compare_strings(e, a) == 1
+}
+
+fn test_sort() {
+	mut vals := [
+		'arr',
+		'an',
+		'a',
+		'any',
+	]
+	len := vals.len
+	vals.sort()
+	assert len == vals.len
+	assert vals[0] == 'a'
+	assert vals[1] == 'an'
+	assert vals[2] == 'any'
+	assert vals[3] == 'arr'
+}
+
+fn test_sort_reverse() {
+	mut vals := [
+		'arr',
+		'an',
+		'a',
+		'any',
+	]
+	len := vals.len
+	vals.sort(b > a)
+	assert len == vals.len
+	assert vals[0] == 'a'
+	assert vals[1] == 'an'
+	assert vals[2] == 'any'
+	assert vals[3] == 'arr'
+}
+
+fn test_split_nth() {
+	a := '1,2,3'
+	assert a.split(',').len == 3
+	assert a.split_nth(',', -1).len == 3
+	assert a.split_nth(',', 0).len == 3
+	assert a.split_nth(',', 1).len == 1
+	assert a.split_nth(',', 2).len == 2
+	assert a.split_nth(',', 10).len == 3
+	b := '1::2::3'
+	assert b.split('::').len == 3
+	assert b.split_nth('::', -1).len == 3
+	assert b.split_nth('::', 0).len == 3
+	assert b.split_nth('::', 1).len == 1
+	assert b.split_nth('::', 2).len == 2
+	assert b.split_nth('::', 10).len == 3
+	c := 'ABCDEF'
+	println(c.split('').len)
+	assert c.split('').len == 6
+	assert c.split_nth('', 3).len == 3
+	assert c.split_nth('BC', -1).len == 2
+	d := ','
+	assert d.split(',').len == 2
+	assert d.split_nth('', 3).len == 1
+	assert d.split_nth(',', -1).len == 2
+	assert d.split_nth(',', 3).len == 2
+	e := ',,,0,,,,,a,,b,'
+	assert e.split(',,').len == 5
+	assert e.split_nth(',,', 3).len == 3
+	assert e.split_nth(',', -1).len == 12
+	assert e.split_nth(',', 3).len == 3
+}
+
+fn test_split_nth_values() {
+	line := 'CMD=eprintln(phase=1)'
+
+	a0 := line.split_nth('=', 0)
+	assert a0.len == 3
+	assert a0[0] == 'CMD'
+	assert a0[1] == 'eprintln(phase'
+	assert a0[2] == '1)'
+
+	a1 := line.split_nth('=', 1)
+	assert a1.len == 1
+	assert a1[0] == 'CMD=eprintln(phase=1)'
+
+	a2 := line.split_nth('=', 2)
+	assert a2.len == 2
+	assert a2[0] == 'CMD'
+	assert a2[1] == 'eprintln(phase=1)'
+
+	a3 := line.split_nth('=', 3)
+	assert a3.len == 3
+	assert a3[0] == 'CMD'
+	assert a3[1] == 'eprintln(phase'
+	assert a3[2] == '1)'
+
+	a4 := line.split_nth('=', 4)
+	assert a4.len == 3
+	assert a4[0] == 'CMD'
+	assert a4[1] == 'eprintln(phase'
+	assert a4[2] == '1)'
+}
+
+fn test_split() {
+	mut s := 'volt/twitch.v:34'
+	mut vals := s.split(':')
+	assert vals.len == 2
+	assert vals[0] == 'volt/twitch.v'
+	assert vals[1] == '34'
+	// /////////
+	s = '2018-01-01z13:01:02'
+	vals = s.split('z')
+	assert vals.len == 2
+	assert vals[0] == '2018-01-01'
+	assert vals[1] == '13:01:02'
+	// //////////
+	s = '4627a862c3dec29fb3182a06b8965e0025759e18___1530207969___blue'
+	vals = s.split('___')
+	assert vals.len == 3
+	assert vals[0] == '4627a862c3dec29fb3182a06b8965e0025759e18'
+	assert vals[1] == '1530207969'
+	assert vals[2] == 'blue'
+	// /////////
+	s = 'lalala'
+	vals = s.split('a')
+	assert vals.len == 4
+	assert vals[0] == 'l'
+	assert vals[1] == 'l'
+	assert vals[2] == 'l'
+	assert vals[3] == ''
+	// /////////
+	s = 'awesome'
+	a := s.split('')
+	assert a.len == 7
+	assert a[0] == 'a'
+	assert a[1] == 'w'
+	assert a[2] == 'e'
+	assert a[3] == 's'
+	assert a[4] == 'o'
+	assert a[5] == 'm'
+	assert a[6] == 'e'
+	// /////////
+	s = 'wavy turquoise bags'
+	vals = s.split(' bags')
+	assert vals.len == 2
+	assert vals[0] == 'wavy turquoise'
+	assert vals[1] == ''
+}
+
+/*
+fn test_trim_space() {
+	a := ' a '
+	assert a.trim_space() == 'a'
+	code := '
+
+fn main() {
+        println(2)
+}
+
+'
+	code_clean := 'fn main() {
+        println(2)
+}'
+	assert code.trim_space() == code_clean
+}*/
+
+/*
+fn test_join() {
+	mut strings := ['a', 'b', 'c']
+	mut s := strings.join(' ')
+	assert s == 'a b c'
+	strings = [
+		'one
+two ',
+		'three!
+four!',
+	]
+	s = strings.join(' ')
+	assert s.contains('one') && s.contains('two ') && s.contains('four')
+	empty := []string{len: 0}
+	assert empty.join('A') == ''
+}*/
+
+fn test_clone() {
+	mut a := 'a'
+	a += 'a'
+	a += 'a'
+	b := a
+	c := a.clone()
+	assert c == a
+	assert c == 'aaa'
+	assert b == 'aaa'
+}
+
+fn test_replace() {
+	a := 'hello man!'
+	mut b := a.replace('man', 'world')
+	assert b == ('hello world!')
+	b = b.replace('!', '')
+	assert b == ('hello world')
+	b = b.replace('h', 'H')
+	assert b == ('Hello world')
+	b = b.replace('foo', 'bar')
+	assert b == ('Hello world')
+	s := 'hey man how are you'
+	assert s.replace('man ', '') == 'hey how are you'
+	lol := 'lol lol lol'
+	assert lol.replace('lol', 'LOL') == 'LOL LOL LOL'
+	b = 'oneBtwoBBthree'
+	assert b.replace('B', '') == 'onetwothree'
+	b = '*charptr'
+	assert b.replace('charptr', 'byteptr') == '*byteptr'
+	c := 'abc'
+	println(c.replace('', '-'))
+	// assert c.replace('', '-') == c
+	v := 'a   b c d'
+	assert v.replace('  ', ' ') == 'a  b c d'
+}
+
+fn test_replace_each() {
+	s := 'hello man man :)'
+	q := s.replace_each([
+		'man',
+		'dude',
+		'hello',
+		'hey',
+	])
+	assert q == 'hey dude dude :)'
+	bb := '[b]bold[/b] [code]code[/code]'
+	assert bb.replace_each([
+		'[b]',
+		'<b>',
+		'[/b]',
+		'</b>',
+		'[code]',
+		'<code>',
+		'[/code]',
+		'</code>',
+	]) == '<b>bold</b> <code>code</code>'
+	bb2 := '[b]cool[/b]'
+	assert bb2.replace_each([
+		'[b]',
+		'<b>',
+		'[/b]',
+		'</b>',
+	]) == '<b>cool</b>'
+	t := 'aaaaaaaa'
+	y := t.replace_each([
+		'aa',
+		'b',
+	])
+	assert y == 'bbbb'
+	s2 := 'hello_world hello'
+	assert s2.replace_each(['hello_world', 'aaa', 'hello', 'bbb']) == 'aaa bbb'
+}
+
+fn test_itoa() {
+	num := 777
+	assert num.str() == '777'
+	big := 7779998
+	assert big.str() == '7779998'
+	a := 3
+	assert a.str() == '3'
+	b := 5555
+	assert b.str() == '5555'
+	zero := 0
+	assert zero.str() == '0'
+	neg := -7
+	assert neg.str() == '-7'
+}
+
+fn test_reassign() {
+	a := 'hi'
+	mut b := a
+	b += '!'
+	assert a == 'hi'
+	assert b == 'hi!'
+}
+
+/*
+fn test_runes() {
+	s := 'привет'
+	assert s.len == 12
+	s2 := 'privet'
+	assert s2.len == 6
+	u := s.runes()
+	assert u.len == 6
+	assert s2.substr(1, 4).len == 3
+	assert s2.substr(1, 4) == 'riv'
+	assert s2[1..4].len == 3
+	assert s2[1..4] == 'riv'
+	assert s2[..4].len == 4
+	assert s2[..4] == 'priv'
+	assert s2[2..].len == 4
+	assert s2[2..] == 'ivet'
+	assert u[1..4].string().len == 6
+	assert u[1..4].string() == 'рив'
+	assert s2.substr(1, 2) == 'r'
+	assert u[1..2].string() == 'р'
+	assert s2.runes()[1] == `r`
+	assert u[1] == `р`
+	first := u[0]
+	last := u[u.len - 1]
+	assert first.str().len == 2
+	assert last.str().len == 2
+}*/
+
+fn test_contains() {
+	s := 'view.v'
+	assert s.contains('vi')
+	assert !s.contains('random')
+	assert ''.contains('')
+	assert 'abc'.contains('')
+}
+
+fn test_contains_any() {
+	assert !'team'.contains_any('i')
+	assert 'fail'.contains_any('ui')
+	assert 'ure'.contains_any('ui')
+	assert 'failure'.contains_any('ui')
+	assert !'foo'.contains_any('')
+	assert !''.contains_any('')
+}
+
+fn test_contains_any_substr() {
+	s := 'Some random text'
+	assert s.contains_any_substr(['false', 'not', 'rand'])
+	assert !s.contains_any_substr(['ABC', 'invalid'])
+	assert ''.contains_any_substr([])
+	assert 'abc'.contains_any_substr([''])
+}
+
+fn test_arr_contains() {
+	a := ['a', 'b', 'c']
+	assert a.contains('b')
+	ints := [1, 2, 3]
+	assert ints.contains(2)
+}
+
+/*
+fn test_to_num() {
+	s := '7'
+	assert s.int() == 7
+	assert s.byte() == 7
+	assert s.u64() == 7
+	f := '71.5 hasdf'
+	// QTODO
+	assert f.f32() == 71.5
+	vals := ['9']
+	assert vals[0].int() == 9
+	big := '93993993939322'
+	assert big.u64() == 93993993939322
+	assert big.i64() == 93993993939322
+}*/
+
+/*
+fn test_inter_format_string() {
+	float_num := 1.52345
+	float_num_string := '-${float_num:.3f}-'
+	//assert float_num_string == '-1.523-'
+	int_num := 7
+	int_num_string := '-${int_num:03d}-'
+	//assert int_num_string == '-007-'
+	ch := `a`
+	ch_string := '-${ch:c}-'
+	//assert ch_string == '-a-'
+	hex_n := 192
+	hex_n_string := '-${hex_n:x}-'
+	assert hex_n_string == '-c0-'
+	oct_n := 192
+	oct_n_string := '-${oct_n:o}-'
+	assert oct_n_string == '-300-'
+	str := 'abc'
+	str_string := '-${str:s}-'
+	assert str_string == '-abc-'
+}*/
+
+/*
+fn test_hash() {
+	s := '10000'
+	assert s.hash() == 46730161
+	s2 := '24640'
+	assert s2.hash() == 47778736
+	s3 := 'Content-Type'
+	assert s3.hash() == 949037134
+	s4 := 'bad_key'
+	assert s4.hash() == -346636507
+	s5 := '24640'
+	// From a map collision test
+	assert s5.hash() % ((1 << 20) - 1) == s.hash() % ((1 << 20) - 1)
+	assert s5.hash() % ((1 << 20) - 1) == 592861
+}*/
+
+fn test_trim() {
+	assert 'banana'.trim('bna') == ''
+	assert 'abc'.trim('ac') == 'b'
+	assert 'aaabccc'.trim('ac') == 'b'
+}
+
+fn test_trim_left() {
+	mut s := 'module main'
+	assert s.trim_left(' ') == 'module main'
+	s = ' module main'
+	assert s.trim_left(' ') == 'module main'
+	// test cutset
+	s = 'banana'
+	assert s.trim_left('ba') == 'nana'
+	assert s.trim_left('ban') == ''
+}
+
+fn test_trim_right() {
+	mut s := 'module main'
+	assert s.trim_right(' ') == 'module main'
+	s = 'module main '
+	assert s.trim_right(' ') == 'module main'
+	// test cutset
+	s = 'banana'
+	assert s.trim_right('na') == 'b'
+	assert s.trim_right('ban') == ''
+}
+
+fn test_all_before() {
+	s := 'fn hello fn'
+	assert s.all_before(' ') == 'fn'
+	assert s.all_before('2') == s
+	assert s.all_before('') == s
+}
+
+fn test_all_before_last() {
+	s := 'fn hello fn'
+	assert s.all_before_last(' ') == 'fn hello'
+	assert s.all_before_last('2') == s
+	assert s.all_before_last('') == s
+}
+
+fn test_all_after() {
+	s := 'fn hello'
+	assert s.all_after('fn ') == 'hello'
+	assert s.all_after('test') == s
+	assert s.all_after('') == s
+	assert s.after('e') == 'llo'
+	x := s.after('e')
+	assert x == 'llo'
+}
+
+fn test_reverse() {
+	println('hello'.reverse())
+	assert 'hello'.reverse() == 'olleh'
+	assert ''.reverse() == ''
+	assert 'a'.reverse() == 'a'
+}
+
+fn test_count() {
+	assert ''.count('') == 0
+	assert ''.count('a') == 0
+	assert 'a'.count('') == 0
+	assert 'aa'.count('a') == 2
+	assert 'aa'.count('aa') == 1
+	assert 'aabbaa'.count('aa') == 2
+	assert 'bbaabb'.count('aa') == 1
+}
+
+fn test_lower() {
+	mut s := 'A'
+	assert !s.is_lower()
+	assert s.to_lower() == 'a'
+	assert s.to_lower().len == 1
+	s = 'HELLO'
+	assert !s.is_lower()
+	assert s.to_lower() == 'hello'
+	assert s.to_lower().len == 5
+	s = 'Aloha'
+	assert !s.is_lower()
+	assert s.to_lower() == 'aloha'
+	s = 'Have A nice Day!'
+	assert !s.is_lower()
+	assert s.to_lower() == 'have a nice day!'
+	s = 'hi'
+	assert s.is_lower()
+	assert s.to_lower() == 'hi'
+	assert 'aloha!'[0] == `a`
+	assert 'aloha!'[5] == `!`
+}
+
+fn test_upper() {
+	mut s := 'a'
+	assert !s.is_upper()
+	assert s.to_upper() == 'A'
+	assert s.to_upper().len == 1
+	s = 'hello'
+	assert !s.is_upper()
+	assert s.to_upper() == 'HELLO'
+	assert s.to_upper().len == 5
+	s = 'Aloha'
+	assert !s.is_upper()
+	assert s.to_upper() == 'ALOHA'
+	s = 'have a nice day!'
+	assert !s.is_upper()
+	assert s.to_upper() == 'HAVE A NICE DAY!'
+	s = 'HI'
+	assert s.is_upper()
+	assert s.to_upper() == 'HI'
+}
+
+fn test_capitalize() {
+	mut s := 'hello'
+	assert !s.is_capital()
+	assert s.capitalize() == 'Hello'
+	s = 'test'
+	assert !s.is_capital()
+	assert s.capitalize() == 'Test'
+	s = 'i am ray'
+	assert !s.is_capital()
+	assert s.capitalize() == 'I am ray'
+	s = ''
+	assert !s.is_capital()
+	assert s.capitalize() == ''
+	s = 'TEST IT'
+	assert !s.is_capital()
+	assert s.capitalize() == 'TEST IT'
+	s = 'Test it'
+	assert s.is_capital()
+	assert s.capitalize() == 'Test it'
+	assert 'GameMission_t'.capitalize() == 'GameMission_t'
+}
+
+fn test_title() {
+	mut s := 'hello world'
+	assert !s.is_title()
+	assert s.title() == 'Hello World'
+	s = 'HELLO WORLD'
+	assert !s.is_title()
+	assert s.title() == 'HELLO WORLD'
+	s = 'Hello World'
+	assert s.is_title()
+	assert s.title() == 'Hello World'
+}
+
+fn test_for_loop() {
+	mut i := 0
+	s := 'abcd'
+
+	for c in s {
+		assert c == s[i]
+		i++
+	}
+}
+
+fn test_for_loop_two() {
+	s := 'abcd'
+
+	for i, c in s {
+		assert c == s[i]
+	}
+}
+
+fn test_quote() {
+	a := `'`
+	println('testing double quotes')
+	b := 'hi'
+	assert b == 'hi'
+	// assert a.str() == "'"
+}
+
+/*
+fn test_limit() {
+	s := 'hello'
+	assert s.limit(2) == 'he'
+	assert s.limit(9) == s
+	assert s.limit(0) == ''
+	// assert s.limit(-1) == ''
+}*/
+
+fn test_repeat() {
+	s1 := 'V! '
+	assert s1.repeat(5) == 'V! V! V! V! V! '
+	assert s1.repeat(1) == s1
+	assert s1.repeat(0) == ''
+	s2 := ''
+	assert s2.repeat(5) == s2
+	assert s2.repeat(1) == s2
+	assert s2.repeat(0) == s2
+	// TODO Add test for negative values
+}
+
+fn test_starts_with() {
+	s := 'V Programming Language'
+	assert s.starts_with('V') == true
+	assert s.starts_with('V Programming') == true
+	assert s.starts_with('Language') == false
+}
+
+fn test_trim_prefix() {
+	s := 'V Programming Language'
+	assert s.trim_prefix('V ') == 'Programming Language'
+	assert s.trim_prefix('V Programming ') == 'Language'
+	assert s.trim_prefix('Language') == s
+
+	s2 := 'TestTestTest'
+	assert s2.trim_prefix('Test') == 'TestTest'
+	assert s2.trim_prefix('TestTest') == 'Test'
+
+	s3 := '123Test123Test'
+	assert s3.trim_prefix('123') == 'Test123Test'
+	assert s3.trim_prefix('123Test') == '123Test'
+}
+
+fn test_trim_suffix() {
+	s := 'V Programming Language'
+	assert s.trim_suffix(' Language') == 'V Programming'
+	assert s.trim_suffix(' Programming Language') == 'V'
+	assert s.trim_suffix('V') == s
+
+	s2 := 'TestTestTest'
+	assert s2.trim_suffix('Test') == 'TestTest'
+	assert s2.trim_suffix('TestTest') == 'Test'
+
+	s3 := '123Test123Test'
+	assert s3.trim_suffix('123') == s3
+	assert s3.trim_suffix('123Test') == '123Test'
+}
+
+fn test_raw() {
+	raw := r'raw\nstring'
+	lines := raw.split('\n')
+	println(lines)
+	assert lines.len == 1
+	println('raw string: "$raw"')
+
+	raw2 := r'Hello V\0'
+	assert raw2[7] == `\\`
+	assert raw2[8] == `0`
+
+	raw3 := r'Hello V\x00'
+	assert raw3[7] == `\\`
+	assert raw3[8] == `x`
+	assert raw3[9] == `0`
+	assert raw3[10] == `0`
+}
+
+fn test_raw_with_quotes() {
+	raw := r"some'" + r'"thing' // " should be escaped in the generated C code
+	// assert raw[0] == `s`
+	// assert raw[5] == `"`
+	// assert raw[6] == `t`
+}
+
+fn test_escape() {
+	a := 10
+	println("\"$a")
+	// assert "\"$a" == '"10'
+}
+
+fn test_atoi() {
+	assert '234232'.int() == 234232
+	assert '-9009'.int() == -9009
+	assert '0'.int() == 0
+	for n in -10000 .. 100000 {
+		s := n.str()
+		assert s.int() == n
+	}
+}
+
+fn test_raw_inter() {
+	world := 'world'
+	println(world)
+	s := r'hello\n$world'
+	assert s == r'hello\n$world'
+	assert s.contains('$')
+}
+
+fn test_c_r() {
+	// This used to break because of r'' and c''
+	c := 42
+	println('$c')
+	r := 50
+	println('$r')
+}
+
+fn test_inter_before_comp_if() {
+	s := '123'
+	// This used to break ('123 $....')
+	$if linux {
+		println(s)
+	}
+	assert s == '123'
+}
+
+fn test_double_quote_inter() {
+	a := 1
+	b := 2
+	println('$a $b')
+	assert '$a $b' == '1 2'
+	assert '$a $b' == '1 2'
+}
+
+fn foo(b byte) byte {
+	return b - 10
+}
+
+fn filter(b byte) bool {
+	return b != `a`
+}
+
+/*
+fn test_split_into_lines() {
+	line_content := 'Line'
+	text_crlf := '$line_content\r\n$line_content\r\n$line_content'
+	lines_crlf := text_crlf.split_into_lines()
+
+	assert lines_crlf.len == 3
+	for line in lines_crlf {
+		assert line == line_content
+	}
+
+	text_lf := '$line_content\n$line_content\n$line_content'
+	lines_lf := text_lf.split_into_lines()
+
+	assert lines_lf.len == 3
+	for line in lines_lf {
+		assert line == line_content
+	}
+}
+*/
+fn test_string_literal_with_backslash() {
+	a := 'HelloWorld'
+	assert a == 'HelloWorld'
+
+	b := 'OneTwoThree'
+	assert b == 'OneTwoThree'
+}
+
+/*
+type MyString = string
+
+fn test_string_alias() {
+	s := MyString('hi')
+	ss := s + '!'
+}
+*/
+
+// sort an array of structs, by their string field values
+
+struct Ka {
+	s string
+	i int
+}
+
+fn test_sorter() {
+	mut arr := [
+		Ka{
+			s: 'bbb'
+			i: 100
+		},
+		Ka{
+			s: 'aaa'
+			i: 101
+		},
+		Ka{
+			s: 'ccc'
+			i: 102
+		},
+	]
+	cmp := fn (a &Ka, b &Ka) int {
+		return compare_strings(a.s, b.s)
+	}
+	arr.sort_with_compare(cmp)
+	assert arr[0].s == 'aaa'
+	assert arr[0].i == 101
+	assert arr[1].s == 'bbb'
+	assert arr[1].i == 100
+	assert arr[2].s == 'ccc'
+	assert arr[2].i == 102
+}
+
+fn test_fields() {
+	assert 'a bcde'.fields() == ['a', 'bcde']
+	assert '  sss \t  ssss '.fields() == ['sss', 'ssss']
+	assert '\n xyz \t abc   def'.fields() == ['xyz', 'abc', 'def']
+	assert 'hello'.fields() == ['hello']
+	assert ''.fields() == []
+}
+
+/*
+fn test_interpolation_after_quoted_variable_still_works() {
+	rr := 'abc'
+	tt := 'xyz'
+
+	// Basic interpolation, no internal quotes
+	yy := 'Replacing $rr with $tt'
+	assert yy == 'Replacing abc with xyz'
+
+	// Interpolation after quoted variable ending with 'r'quote
+	// that may be mistaken with the start of a raw string,
+	// ensure that it is not.
+	ss := 'Replacing "$rr" with "$tt"'
+	assert ss == 'Replacing "abc" with "xyz"'
+	zz := "Replacing '$rr' with '$tt'"
+	assert zz == "Replacing 'abc' with 'xyz'"
+
+	// Interpolation after quoted variable ending with 'c'quote
+	// may be mistaken with the start of a c string, so
+	// check it is not.
+	cc := 'abc'
+	ccc := "Replacing '$cc' with '$tt'"
+	assert ccc == "Replacing 'abc' with 'xyz'"
+	cccq := 'Replacing "$cc" with "$tt"'
+	assert cccq == 'Replacing "abc" with "xyz"'
+}
+*/
+fn test_index_any() {
+	x := 'abcdefghij'
+	assert x.index_any('ef') == 4
+	assert x.index_any('fe') == 4
+}
diff --git a/vlib/v/gen/js/infix.v b/vlib/v/gen/js/infix.v
index 767ce56a72..e6d55fc2f2 100644
--- a/vlib/v/gen/js/infix.v
+++ b/vlib/v/gen/js/infix.v
@@ -287,7 +287,11 @@ fn (mut g JsGen) infix_in_not_in_op(node ast.InfixExpr) {
 		g.gen_deref_ptr(node.right_type)
 		g.write(',')
 		g.expr(node.left)
-		g.write('))')
+		g.write(')')
+		if node.op == .not_in {
+			g.write('.valueOf()')
+		}
+		g.write(')')
 		return
 	} else if r_sym.unaliased_sym.kind == .map {
 		g.expr(node.right)
diff --git a/vlib/v/gen/js/js.v b/vlib/v/gen/js/js.v
index be0f8cf132..c87eb5e232 100644
--- a/vlib/v/gen/js/js.v
+++ b/vlib/v/gen/js/js.v
@@ -145,7 +145,7 @@ pub fn gen(files []&ast.File, table &ast.Table, pref &pref.Preferences) string {
 			g.gen_builtin_type_defs()
 			g.writeln('Object.defineProperty(array.prototype,"len", { get: function() {return new int(this.arr.arr.length);}, set: function(l) { this.arr.arr.length = l.valueOf(); } }); ')
 			g.writeln('Object.defineProperty(string.prototype,"len", { get: function() {return new int(this.str.length);}, set: function(l) {/* ignore */ } }); ')
-			g.writeln('Object.defineProperty(map.prototype,"len", { get: function() {return new int(this.map.length);}, set: function(l) { this.map.length = l.valueOf(); } }); ')
+			g.writeln('Object.defineProperty(map.prototype,"len", { get: function() {return new int(this.map.size);}, set: function(l) { this.map.size = l.valueOf(); } }); ')
 			g.writeln('Object.defineProperty(array.prototype,"length", { get: function() {return new int(this.arr.arr.length);}, set: function(l) { this.arr.arr.length = l.valueOf(); } }); ')
 			g.generated_builtin = true
 		}
@@ -1182,7 +1182,7 @@ fn (mut g JsGen) gen_assign_stmt(stmt ast.AssignStmt, semicolon bool) {
 				g.write('.val')
 			}
 
-			if g.inside_map_set && op == .assign {
+			if false && g.inside_map_set && op == .assign {
 				g.inside_map_set = false
 				g.write(', ')
 				g.expr(val)
@@ -2338,15 +2338,24 @@ fn (mut g JsGen) gen_index_expr(expr ast.IndexExpr) {
 
 		if expr.is_setter {
 			g.inside_map_set = true
-			g.write('.map.set(')
+			g.write('.getOrSet(')
 		} else {
 			g.write('.map.get(')
 		}
 		g.expr(expr.index)
 		g.write('.\$toJS()')
-		if !expr.is_setter {
-			g.write(')')
+		if expr.is_setter {
+			// g.write(', ${g.to_js_typ_val(left_typ.)')
+			match left_typ.info {
+				ast.Map {
+					g.write(', ${g.to_js_typ_val(left_typ.info.value_type)}')
+				}
+				else {
+					verror('unreachable')
+				}
+			}
 		}
+		g.write(')')
 	} else if left_typ.kind == .string {
 		if expr.is_setter {
 			// TODO: What's the best way to do this?