Merge pull request #262 from novemberborn/source-map-pragma

Support source map pragmas for stack traces

Author: sindresorhus

lib/babel.js

@@ -1,15 +1,16 @@
 'use strict';
 var sourceMapCache = Object.create(null);
 
-require('source-map-support').install({
+var sourceMapSupport = require('source-map-support');
+sourceMapSupport.install({
 	retrieveSourceMap: function (source) {
 		if (sourceMapCache[source]) {
 			return {
 				url: source,
 				map: sourceMapCache[source]
 			};
 		}
-		return null;
+		return sourceMapSupport.retrieveSourceMap(source);
 	}
 });
 

test/cli.js

@@ -166,8 +166,6 @@ test('uncaught exception will be reported to console', function (t) {
 	execCli('fixture/uncaught-exception.js', function (err, stdout, stderr) {
 		t.ok(err);
 		t.true(/Can't catch me!/.test(stderr));
-		t.match(stderr, /^.*?at.*?bar\b.*uncaught-exception.js:12.*$/m);
-		t.match(stderr, /^.*?at.*?foo\b.*uncaught-exception.js:8.*$/m);
 		// TODO(jamestalmage): This should get printed, but we reject the promise (ending all tests) instead of just ending that one test and reporting.
 		// t.ok(/1 uncaught exception[^s]/.test(stdout));
 		t.end();
@@ -194,6 +192,26 @@ test('throwing a anonymous function will report the function to the console', fu
 	});
 });
 
+test('stack traces for exceptions are corrected using a source map', function (t) {
+	execCli('fixture/source-map-exception.js', function (err, stdout, stderr) {
+		t.ok(err);
+		t.true(/Can't catch me!/.test(stderr));
+		t.match(stderr, /^.*?at.*?bar\b.*source-map-exception.js:12.*$/m);
+		t.match(stderr, /^.*?at.*?foo\b.*source-map-exception.js:8.*$/m);
+		t.end();
+	});
+});
+
+test('stack traces for exceptions are corrected using a source map, found via a pragma', function (t) {
+	execCli('fixture/source-map-pragma-exception.js', function (err, stdout, stderr) {
+		t.ok(err);
+		t.true(/Can't catch me!/.test(stderr));
+		t.match(stderr, /^.*?at.*?bar\b.*source-with-source-map-pragma.js:8.*$/m);
+		t.match(stderr, /^.*?at.*?foo\b.*source-with-source-map-pragma.js:4.*$/m);
+		t.end();
+	});
+});
+
 test('absolute paths in CLI', function (t) {
 	t.plan(2);
 

test/fixture/source-map-exception.js

@@ -0,0 +1,13 @@
+const test = require('../../');
+
+test('throw an uncaught exception', t => {
+	setImmediate(foo);
+});
+
+function foo() {
+	bar();
+}
+
+function bar() {
+	throw new Error(`Can't catch me!`)
+}

test/fixture/source-map-pragma-exception.js

@@ -0,0 +1,6 @@
+const test = require('../../');
+const foo = require('./source-with-source-map-pragma');
+
+test('throw an uncaught exception', t => {
+	setImmediate(foo);
+});

test/fixture/source-with-source-map-pragma.js

@@ -0,0 +1,25 @@
+"use strict";
+
+module.exports = foo;
+
+function foo() {
+	bar();
+}
+
+function bar() {
+	throw new Error("Can't catch me!");
+}
+
+//# sourceMappingURL=./source-with-source-map-pragma.map
+
+/* original source:
+module.exports = foo
+
+function foo() {
+	bar()
+}
+
+function bar() {
+	throw new Error(`Can't catch me!`)
+}
+*/

test/fixture/source-with-source-map-pragma.map

@@ -1,13 +1,7 @@
 const test = require('../../');
 
 test('throw an uncaught exception', t => {
-	setImmediate(foo);
+	setImmediate(() => {
+		throw new Error(`Can't catch me!`)
+	});
 });
-
-function foo() {
-	bar();
-}
-
-function bar() {
-	throw new Error(`Can't catch me!`)
-}