JS: Recognize 'lang' attribute of script tags

Author: asgerf

javascript/extractor/src/com/semmle/js/extractor/HTMLExtractor.java

@@ -1,12 +1,14 @@
 package com.semmle.js.extractor;
 
+import java.util.regex.Pattern;
+
 import com.semmle.js.extractor.ExtractorConfig.Platform;
 import com.semmle.js.extractor.ExtractorConfig.SourceType;
 import com.semmle.js.parser.ParseError;
 import com.semmle.util.data.StringUtil;
 import com.semmle.util.trap.TrapWriter;
 import com.semmle.util.trap.TrapWriter.Label;
-import java.util.regex.Pattern;
+
 import net.htmlparser.jericho.Attribute;
 import net.htmlparser.jericho.Attributes;
 import net.htmlparser.jericho.CharacterReference;
@@ -143,6 +145,10 @@ private SourceType getScriptSourceType(Element script) {
     String scriptType = getAttributeValueLC(script, "type");
     String scriptLanguage = getAttributeValueLC(script, "language");
 
+    if (scriptLanguage == null) { // Vue templates use 'lang' instead of 'language'.
+      scriptLanguage = getAttributeValueLC(script, "lang");
+    }
+
     // if `type` and `language` are both either missing, contain the
     // string "javascript", or if `type` is the string "text/jsx", this is a plain script
     if ((scriptType == null || scriptType.contains("javascript") || "text/jsx".equals(scriptType))

javascript/ql/test/library-tests/TypeScript/EmbeddedInScript/Test.expected

@@ -0,0 +1,2 @@
+classDeclaration
+exprType

javascript/ql/test/library-tests/TypeScript/EmbeddedInScript/Test.ql

@@ -0,0 +1,5 @@
+import javascript
+
+query ClassDefinition classDeclaration() { any() }
+
+query Type exprType(Expr e) { result = e.getType() }

javascript/ql/test/library-tests/TypeScript/EmbeddedInScript/test.vue

@@ -0,0 +1,5 @@
+<script lang='ts'>
+  export default class MyComponent {
+      x!: number;
+  }
+</script>