Basic tests and inline source maps when native source maps are enabled

- Added check to not patch `Error.prepareStackTrace` if it has already been patched by another library. - Always attach inline source maps if `--enable-source-map` is set. - Added some basic tests for stack trace.

Author: STRd6

docs/v2/browser-compiler-legacy/coffeescript.js

@@ -5364,27 +5364,27 @@ <h3>Bound generator functions</h3>
  <h3>Classes are compiled to ES2015 classes</h3>
 <p>ES2015 classes and their methods have some restrictions beyond those on regular functions.</p>
 <p>Class constructors can’t be invoked without <code>new</code>:</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee">(<span class="keyword">class</span>)()
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee">(<span class="class"><span class="keyword">class</span>)()</span>
 <span class="comment"># Throws a TypeError at runtime</span>
 </code></pre>
 </blockquote><p>ES2015 classes don’t allow bound (fat arrow) methods. The CoffeeScript compiler goes through some contortions to preserve support for them, but one thing that can’t be accommodated is calling a bound method before it is bound:</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="keyword">class</span> <span class="title class_">Base</span>
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="class"><span class="keyword">class</span> <span class="title">Base</span></span>
  constructor: <span class="function">-&gt;</span>
  @onClick() <span class="comment"># This works</span>
  clickHandler = @onClick
  clickHandler() <span class="comment"># This throws a runtime error</span>
 
-<span class="keyword">class</span> <span class="title class_">Component</span> <span class="keyword">extends</span> <span class="title class_ inherited__">Base</span>
+<span class="class"><span class="keyword">class</span> <span class="title">Component</span> <span class="keyword">extends</span> <span class="title">Base</span></span>
  onClick: <span class="function">=&gt;</span>
  console.log <span class="string">&#x27;Clicked!&#x27;</span>, @
 </code></pre>
 </blockquote><p>Class methods can’t be used with <code>new</code> (uncommon):</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="keyword">class</span> <span class="title class_">Namespace</span>
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="class"><span class="keyword">class</span> <span class="title">Namespace</span></span>
  @Klass = <span class="function">-&gt;</span>
 <span class="keyword">new</span> Namespace.Klass <span class="comment"># Throws a TypeError at runtime</span>
 </code></pre>
 </blockquote><p>Due to the hoisting required to compile to ES2015 classes, dynamic keys in class methods can’t use values from the executable class body unless the methods are assigned in prototype style.</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="keyword">class</span> <span class="title class_">A</span>
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="class"><span class="keyword">class</span> <span class="title">A</span></span>
  name = <span class="string">&#x27;method&#x27;</span>
  <span class="string">&quot;<span class="subst">#{name}</span>&quot;</span>: <span class="function">-&gt;</span> <span class="comment"># This method will be named &#x27;undefined&#x27;</span>
  @::[name] = <span class="function">-&gt;</span> <span class="comment"># This will work; assigns to `A.prototype.method`</span>
@@ -5394,11 +5394,11 @@ <h3>Classes are compiled to ES2015 classes</h3>
  <section id="breaking-changes-super-this">
  <h3><code>super</code> and <code>this</code></h3>
 <p>In the constructor of a derived class (a class that <code>extends</code> another class), <code>this</code> cannot be used before calling <code>super</code>:</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="keyword">class</span> <span class="title class_">B</span> <span class="keyword">extends</span> <span class="title class_ inherited__">A</span>
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="class"><span class="keyword">class</span> <span class="title">B</span> <span class="keyword">extends</span> <span class="title">A</span></span>
  constructor: <span class="function">-&gt;</span> this <span class="comment"># Throws a compiler error</span>
 </code></pre>
 </blockquote><p>This also means you cannot pass a reference to <code>this</code> as an argument to <code>super</code> in the constructor of a derived class:</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="keyword">class</span> <span class="title class_">B</span> <span class="keyword">extends</span> <span class="title class_ inherited__">A</span>
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="class"><span class="keyword">class</span> <span class="title">B</span> <span class="keyword">extends</span> <span class="title">A</span></span>
  constructor: <span class="function"><span class="params">(@arg)</span> -&gt;</span>
  super @arg <span class="comment"># Throws a compiler error</span>
 </code></pre>
@@ -5447,7 +5447,7 @@ <h3><code>super</code> and <code>this</code></h3>
  <section id="breaking-changes-super-extends">
  <h3><code>super</code> and <code>extends</code></h3>
 <p>Due to a syntax clash with <code>super</code> with accessors, “bare” <code>super</code> (the keyword <code>super</code> without parentheses) no longer compiles to a super call forwarding all arguments.</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="keyword">class</span> <span class="title class_">B</span> <span class="keyword">extends</span> <span class="title class_ inherited__">A</span>
+<blockquote class="uneditable-code-block"><pre><code class="language-coffee"><span class="class"><span class="keyword">class</span> <span class="title">B</span> <span class="keyword">extends</span> <span class="title">A</span></span>
  foo: <span class="function">-&gt;</span> super
  <span class="comment"># Throws a compiler error</span>
 </code></pre>
@@ -5704,7 +5704,7 @@ <h3>Argument parsing and shebang (<code>#!</code>) lines</h3>
 console.log x
 </code></pre>
 </blockquote><p>If this were saved as <code>executable.coffee</code>, it could be made executable and run:</p>
-<blockquote class="uneditable-code-block"><pre><code class="language-bash">▶ <span class="built_in">chmod</span> +x ./executable.coffee
+<blockquote class="uneditable-code-block"><pre><code class="language-bash">▶ chmod +x ./executable.coffee
 ▶ ./executable.coffee
 4
 </code></pre>

docs/v2/browser-compiler-modern/coffeescript.js

@@ -32712,6 +32712,7 @@ <h2>Another heading</h2>
 <script type="text/x-coffeescript" class="test" id="sourcemap">
 return if global.testingBrowser
 
+{spawn} = require('child_process')
 SourceMap = require '../src/sourcemap'
 
 vlqEncodedValues = [
@@ -32776,6 +32777,52 @@ <h2>Another heading</h2>
  arrayEq v3SourceMap.sources, ['tempus_fugit.coffee']
  eq v3SourceMap.sourceRoot, './www_root/coffee/'
 
+test "native source maps", ->
+ new Promise (resolve, reject) ->
+ proc = spawn "node", [
+ "--enable-source-maps"
+ "-r", "./register.js"
+ "-r", "./test/integration/error.coffee"
+ ]
+
+ # proc.stdout.setEncoding('utf8')
+ # proc.stdout.on 'data', (s) -> console.log(s)
+ err = ""
+ proc.stderr.setEncoding('utf8')
+ proc.stderr.on 'data', (s) -> err += s
+ proc.on 'exit', (status) ->
+ try
+ equal status, 1
+
+ [_, line] = err.match /error\.coffee:(\d+)/
+ equal line, 3 # Mapped source line
+ resolve()
+ catch e
+ reject(e)
+
+test "don't change stack traces if another library has patched `Error.prepareStackTrace`", ->
+ new Promise (resolve, reject) ->
+ proc = spawn "node", [
+ "-r", "./test/integration/prepare_stack_trace.js",
+ "-r", "./register.js",
+ "-r", "./test/integration/error.coffee",
+ ]
+
+ # proc.stdout.setEncoding('utf8')
+ # proc.stdout.on 'data', (s) -> console.log(s)
+ err = ""
+ proc.stderr.setEncoding('utf8')
+ proc.stderr.on 'data', (s) -> err += s
+ proc.on 'exit', (status) ->
+ try
+ equal status, 1
+
+ [_, line] = err.match /error\.coffee:(\d+)/
+ equal line, 4 # Unmapped source line
+ resolve()
+ catch e
+ reject(e)
+
 </script>
 <script type="text/x-coffeescript" class="test" id="strict">
 # Strict Early Errors

docs/v2/index.html

@@ -59,7 +59,10 @@ exports.compile = compile = withPrettyErrors (code, options = {}) ->
  # Always generate a source map if no filename is passed in, since without a
  # a filename we have no way to retrieve this source later in the event that
  # we need to recompile it to get a source map for `prepareStackTrace`.
- generateSourceMap = options.sourceMap or options.inlineMap or not options.filename?
+ generateSourceMap = options.sourceMap or
+ options.inlineMap or
+ nativeSourceMaps or
+ not options.filename?
  filename = options.filename or '<anonymous>'
 
  checkShebangLine filename, code
@@ -158,7 +161,7 @@ exports.compile = compile = withPrettyErrors (code, options = {}) ->
  if v3SourceMap and transpilerOutput.map
  v3SourceMap = transpilerOutput.map
 
- if options.inlineMap
+ if options.inlineMap or nativeSourceMaps
  encoded = base64encode JSON.stringify v3SourceMap
  sourceMapDataURI = "//# sourceMappingURL=data:application/json;base64,#{encoded}"
  sourceURL = "//# sourceURL=#{options.filename ? 'coffeescript'}"
@@ -246,7 +249,11 @@ parser.yy.parseError = (message, {token}) ->
  # from the lexer.
  helpers.throwSyntaxError "unexpected #{errorText}", errorLoc
 
-if process.execArgv.includes('--enable-source-maps') or process.env.NODE_OPTIONS?.includes('--enable-source-maps')
+# Use native source maps rather than monkey patching `Error.prepareStackTrace`
+# if native source maps are enabled. Do not patch `Error.prepareStackTrace`
+# if another library has patched it since that would break them.
+nativeSourceMaps = process.execArgv.includes('--enable-source-maps') or process.env.NODE_OPTIONS?.includes('--enable-source-maps')
+if nativeSourceMaps or Error.prepareStackTrace
  registerCompiled = ->
 else
  # For each compiled file, save its source in memory in case we need to

docs/v2/test.html

@@ -0,0 +1,3 @@
+# This file throws an error on line 3. It is used for testing error stack traces with sourcemaps.
+module.exports =
+ throw new Error "I am error"

lib/coffeescript-browser-compiler-legacy/coffeescript.js

@@ -0,0 +1,8 @@
+// This simulates a library hooking into `Error.prepareStackTrace` such as Babel
+// via `source-map-support`. This file is used in `../sourcemap.coffee` to test
+// that we won't break a previously installed handler.
+Error.prepareStackTrace = function (err, frames) {
+ return frames.map(function (f) {
+ return `^_^ ${f.getFileName()}:${f.getLineNumber()}:${f.getColumnNumber()}\n`;
+ }).join("");
+};