vlib: add `net.http.mime` (#14516)

vlib/net/http/mime/build.vsh

@@ -0,0 +1,33 @@
+import net.http
+import json
+
+struct MimeType {
+	source       string
+	extensions   []string
+	compressible bool
+	charset      string
+}
+
+fn main() {
+	mt_json := http.get('https://raw.githubusercontent.com/jshttp/mime-db/master/db.json')?
+	mt_map := json.decode(map[string]MimeType, mt_json.text)?
+
+	mut ext_to_mt_str := map[string]string{}
+	for mt_str, mt in mt_map {
+		for ext in mt.extensions {
+			ext_to_mt_str[ext] = mt_str
+		}
+	}
+
+	write_file('db.v', '
+	module mime
+
+	// FILE AUTOGENERATED BY `build.vsh` - DO NOT MANUALLY EDIT
+
+	const (
+		db = $mt_map
+		ext_to_mt_str = $ext_to_mt_str
+	)
+	')?
+	execute('${@VEXE} fmt -w db.v')
+}

vlib/net/http/mime/mime.v

@@ -0,0 +1,39 @@
+module mime
+
+pub struct MimeType {
+	source       string
+	extensions   []string
+	compressible bool
+	charset      string
+}
+
+// returns a `MimeType` for the given MIME type
+pub fn get_complete_mime_type(mt string) MimeType {
+	return db[mt]
+}
+
+// returns the MIME type for the given file extension
+pub fn get_mime_type(ext string) string {
+	return ext_to_mt_str[ext]
+}
+
+// returns a `content-type` header ready to use for the given MIME type
+pub fn get_content_type(mt string) string {
+	mt_struct := db[mt]
+	charset := if mt_struct.charset.len > 0 { mt_struct.charset.to_lower() } else { 'utf-8' }
+	return '$mt; charset=$charset'
+}
+
+// returns the default extension for the given MIME type
+pub fn get_default_ext(mt string) string {
+	return if db[mt].extensions.len > 0 {
+		db[mt].extensions[0]
+	} else {
+		''
+	}
+}
+
+// returns true if the given MIME type exists
+pub fn exists(mt string) bool {
+	return mt in db
+}

vlib/net/http/mime/mime_test.v

@@ -0,0 +1,29 @@
+module mime
+
+fn test_mime() {
+	assert get_complete_mime_type('application/json') == MimeType{
+		source: 'iana'
+		extensions: ['json', 'map']
+		compressible: true
+		charset: 'UTF-8'
+	}
+	assert get_mime_type('json') == 'application/json'
+	assert get_content_type('application/json') == 'application/json; charset=utf-8'
+	assert get_default_ext('application/json') == 'json'
+
+	assert get_complete_mime_type('text/markdown') == MimeType{
+		source: 'iana'
+		extensions: ['md', 'markdown']
+		compressible: true
+		charset: ''
+	}
+	assert get_mime_type('md') == 'text/markdown'
+	assert get_content_type('text/markdown') == 'text/markdown; charset=utf-8'
+	assert get_default_ext('text/markdown') == 'md'
+
+	assert exists('application/json') == true
+	assert exists('udfsbsfib') == false
+
+	assert get_default_ext('application/1d-interleaved-parityfec') == '' // valid mime type without associated extension
+	assert get_default_ext('invalid mime type') == '' // invalid mime type
+}

vlib/vweb/vweb.v

@@ -260,7 +260,7 @@ pub fn (mut ctx Context) file(f_path string) Result {
 		return Result{}
 	}
 	content_type := vweb.mime_types[ext]
-	if content_type == '' {
+	if content_type.len == O {
 		eprintln('no MIME type found for extension $ext')
 		ctx.server_error(500)
 	} else {