Merge pull request microsoft#28489 from ajafff/shebang-comments

 fix comment parsing at start of file

Author: rbuckton

src/compiler/scanner.ts

@@ -661,8 +661,15 @@ namespace ts {
         let pendingKind!: CommentKind;
         let pendingHasTrailingNewLine!: boolean;
         let hasPendingCommentRange = false;
-        let collecting = trailing || pos === 0;
+        let collecting = trailing;
         let accumulator = initial;
+        if (pos === 0) {
+            collecting = true;
+            const shebang = getShebang(text);
+            if (shebang) {
+                pos = shebang.length;
+            }
+        }
         scan: while (pos >= 0 && pos < text.length) {
             const ch = text.charCodeAt(pos);
             switch (ch) {

src/testRunner/tsconfig.json

@@ -43,6 +43,7 @@
         "unittests/asserts.ts",
         "unittests/base64.ts",
         "unittests/builder.ts",
+        "unittests/comments.ts",
         "unittests/compilerCore.ts",
         "unittests/convertToBase64.ts",
         "unittests/customTransforms.ts",

src/testRunner/unittests/comments.ts

@@ -0,0 +1,32 @@
+namespace ts {
+    describe("comment parsing", () => {
+        const withShebang = `#! node
+/** comment */
+// another one
+;`;
+        const noShebang = `/** comment */
+// another one
+;`;
+        const withTrailing = `;/* comment */
+// another one
+`;
+        it("skips shebang", () => {
+            const result = getLeadingCommentRanges(withShebang, 0);
+            assert.isDefined(result);
+            assert.strictEqual(result!.length, 2);
+        });
+
+        it("treats all comments at start of file as leading comments", () => {
+            const result = getLeadingCommentRanges(noShebang, 0);
+            assert.isDefined(result);
+            assert.strictEqual(result!.length, 2);
+        });
+
+        it("returns leading comments if position is not 0", () => {
+            const result = getLeadingCommentRanges(withTrailing, 1);
+            assert.isDefined(result);
+            assert.strictEqual(result!.length, 1);
+            assert.strictEqual(result![0].kind, SyntaxKind.SingleLineCommentTrivia);
+        });
+    });
+}

tests/baselines/reference/shebangBeforeReferences.js

@@ -17,6 +17,7 @@ use(x);
 //// [f.js]
 #!/usr/bin/env node
 "use strict";
+/// <reference path="f.d.ts"/>
 exports.__esModule = true;
 var test_1 = require("test");
 use(test_1.x);