allow ASI before < in typescript type parameters

Author: evanw

CHANGELOG.md

@@ -6,6 +6,12 @@
 
     The upcoming version of TypeScript adds the `moduleSuffixes` field to `tsconfig.json` that introduces more rules to import path resolution. Setting `moduleSuffixes` to `[".ios", ".native", ""]` will try to look at the the relative files `./foo.ios.ts`, `./foo.native.ts`, and finally `./foo.ts` for an import path of `./foo`. Note that the empty string `""` in `moduleSuffixes` is necessary for TypeScript to also look-up `./foo.ts`. This was announced in the [TypeScript 4.7 beta blog post](https://devblogs.microsoft.com/typescript/announcing-typescript-4-7-beta/#resolution-customization-with-modulesuffixes).
 
+* Match the new ASI behavior from TypeScript nightly builds
+
+    This release updates esbuild to match some very recent behavior changes in the TypeScript parser regarding automatic semicolon insertion. For more information, see the following issues:
+
+    * https://github.com/microsoft/TypeScript/issues/48711
+
 ## 0.14.36
 
 * Revert path metadata validation for now ([#2177](https://github.com/evanw/esbuild/issues/2177))

internal/js_parser/ts_parser.go

@@ -380,7 +380,9 @@ func (p *parser) skipTypeScriptTypeWithOpts(level js_ast.L, opts skipTypeOpts) {
 					p.lexer.Next()
 				}
 
-				p.skipTypeScriptTypeArguments(false /* isInsideJSXElement */)
+				if !p.lexer.HasNewlineBefore {
+					p.skipTypeScriptTypeArguments(false /* isInsideJSXElement */)
+				}
 			}
 
 		case js_lexer.TOpenBracket:

internal/js_parser/ts_parser_test.go

@@ -1900,13 +1900,19 @@ func TestTSInstantiationExpression(t *testing.T) {
 	expectParseErrorTS(t, "const a8 = f<number><number>;", "<stdin>: ERROR: Unexpected \";\"\n")
 	expectParseErrorTS(t, "const b1 = f?.<number>;", "<stdin>: ERROR: Expected \"(\" but found \";\"\n")
 
-	// The TypeScript compiler doesn't do semicolon insertion before "<" when
-	// inside "typeof" but does in other situations. Was this an oversight? Not sure,
-	// but we replicate this behavior because it matters when JSX syntax is enabled.
-	expectPrintedTSX(t, "type x = typeof y\n<number>\n1", "1;\n")
-	expectParseErrorTS(t, "type x = typeof y\n<number>\n1\n</number>", "<stdin>: ERROR: Unterminated regular expression\n")
-	expectParseErrorTSX(t, "type x = y\n<number>\n1", "<stdin>: ERROR: Unexpected end of file\n")
-	expectPrintedTSX(t, "type x = y\n<number>\n1\n</number>", "/* @__PURE__ */ React.createElement(\"number\", null, \"1\");\n")
+	// See: https://github.com/microsoft/TypeScript/issues/48711
+	expectPrintedTS(t, "type x = y\n<number>\nz", "z;\n")
+	expectPrintedTSX(t, "type x = y\n<number>\nz\n</number>", "/* @__PURE__ */ React.createElement(\"number\", null, \"z\");\n")
+	expectPrintedTS(t, "type x = typeof y\n<number>\nz", "z;\n")
+	expectPrintedTSX(t, "type x = typeof y\n<number>\nz\n</number>", "/* @__PURE__ */ React.createElement(\"number\", null, \"z\");\n")
+	expectPrintedTS(t, "interface Foo { \n (a: number): a \n <T>(): void \n }", "")
+	expectPrintedTSX(t, "interface Foo { \n (a: number): a \n <T>(): void \n }", "")
+	expectPrintedTS(t, "interface Foo { \n (a: number): typeof a \n <T>(): void \n }", "")
+	expectPrintedTSX(t, "interface Foo { \n (a: number): typeof a \n <T>(): void \n }", "")
+	expectParseErrorTS(t, "type x = y\n<number>\nz\n</number>", "<stdin>: ERROR: Unterminated regular expression\n")
+	expectParseErrorTSX(t, "type x = y\n<number>\nz", "<stdin>: ERROR: Unexpected end of file\n")
+	expectParseErrorTS(t, "type x = typeof y\n<number>\nz\n</number>", "<stdin>: ERROR: Unterminated regular expression\n")
+	expectParseErrorTSX(t, "type x = typeof y\n<number>\nz", "<stdin>: ERROR: Unexpected end of file\n")
 }
 
 func TestTSExponentiation(t *testing.T) {