Improve preparing stack traces

js/compiler.ts

@@ -10,7 +10,6 @@ import { window } from "./globals";
 import * as os from "./os";
 import { RawSourceMap } from "./types";
 import { assert, log, notImplemented } from "./util";
-import * as sourceMaps from "./v8_source_maps";
 
 const EOL = "\n";
 const ASSETS = "$asset$";
@@ -91,7 +90,7 @@ export class ModuleMetaData implements ts.IScriptSnapshot {
     public readonly mediaType: MediaType,
     public readonly sourceCode: SourceCode = "",
     public outputCode: OutputCode = "",
-    public sourceMap: SourceMap = ""
+    public sourceMap: SourceMap | RawSourceMap = ""
   ) {
     if (outputCode !== "" || fileName.endsWith(".d.ts")) {
       this.scriptVersion = "1";
@@ -153,6 +152,8 @@ export class DenoCompiler
   >();
   // A reference to global eval, so it can be monkey patched during testing
   private _globalEval = globalEval;
+  // Keep track of state of the last module requested via `getGeneratedContents`
+  private _lastModule: ModuleMetaData | undefined;
   // A reference to the log utility, so it can be monkey patched during testing
   private _log = log;
   // A map of module file names to module meta data
@@ -376,63 +377,11 @@ export class DenoCompiler
     innerMap.set(moduleSpecifier, fileName);
   }
 
-  /** Setup being able to map back source references back to their source
-   *
-   * TODO is this the best place for this?  It is tightly coupled to how the
-   * compiler works, but it is also tightly coupled to how the whole runtime
-   * environment is bootstrapped.  It also needs efficient access to the
-   * `outputCode` of the module information, which exists inside of the
-   * compiler instance.
-   */
-  private _setupSourceMaps(): void {
-    let lastModule: ModuleMetaData | undefined;
-    sourceMaps.install({
-      installPrepareStackTrace: true,
-
-      getGeneratedContents: (fileName: string): string | RawSourceMap => {
-        this._log("compiler.getGeneratedContents", fileName);
-        if (fileName === "gen/bundle/main.js") {
-          assert(libdeno.mainSource.length > 0);
-          return libdeno.mainSource;
-        } else if (fileName === "main.js.map") {
-          return libdeno.mainSourceMap;
-        } else if (fileName === "deno_main.js") {
-          return "";
-        } else if (!fileName.endsWith(".map")) {
-          const moduleMetaData = this._moduleMetaDataMap.get(fileName);
-          if (!moduleMetaData) {
-            lastModule = undefined;
-            return "";
-          }
-          lastModule = moduleMetaData;
-          return moduleMetaData.outputCode;
-        } else {
-          if (lastModule && lastModule.sourceMap) {
-            // Assuming the the map will always be asked for after the source
-            // code.
-            const { sourceMap } = lastModule;
-            lastModule = undefined;
-            return sourceMap;
-          } else {
-            // Errors thrown here are caught by source-map.
-            throw new Error(`Unable to find source map: "${fileName}"`);
-          }
-        }
-      }
-    });
-    // Pre-compute source maps for main.js.map. This will happen at compile-time
-    // as long as Compiler is instanciated before the snapshot is created..
-    const consumer = sourceMaps.loadConsumer("gen/bundle/main.js");
-    assert(consumer != null);
-    consumer!.computeColumnSpans();
-  }
-
   private constructor() {
     if (DenoCompiler._instance) {
       throw new TypeError("Attempt to create an additional compiler.");
     }
     this._service = this._ts.createLanguageService(this);
-    this._setupSourceMaps();
   }
 
   // Deno specific compiler API
@@ -503,19 +452,55 @@ export class DenoCompiler
       moduleMetaData.outputCode = `${
         outputFile.text
       }\n//# sourceURL=${fileName}`;
-      moduleMetaData.sourceMap = sourceMapFile.text;
+      moduleMetaData.sourceMap = JSON.parse(sourceMapFile.text);
     }
 
     moduleMetaData.scriptVersion = "1";
+    const sourceMap =
+      moduleMetaData.sourceMap === "string"
+        ? moduleMetaData.sourceMap
+        : JSON.stringify(moduleMetaData.sourceMap);
     this._os.codeCache(
       fileName,
       sourceCode,
       moduleMetaData.outputCode,
-      moduleMetaData.sourceMap
+      sourceMap
     );
     return moduleMetaData.outputCode;
   }
 
+  /** Given a fileName, return what was generated by the compiler. */
+  getGeneratedContents = (fileName: string): string | RawSourceMap => {
+    this._log("compiler.getGeneratedContents", fileName);
+    if (fileName === "gen/bundle/main.js") {
+      assert(libdeno.mainSource.length > 0);
+      return libdeno.mainSource;
+    } else if (fileName === "main.js.map") {
+      return libdeno.mainSourceMap;
+    } else if (fileName === "deno_main.js") {
+      return "";
+    } else if (!fileName.endsWith(".map")) {
+      const moduleMetaData = this._moduleMetaDataMap.get(fileName);
+      if (!moduleMetaData) {
+        this._lastModule = undefined;
+        return "";
+      }
+      this._lastModule = moduleMetaData;
+      return moduleMetaData.outputCode;
+    } else {
+      if (this._lastModule && this._lastModule.sourceMap) {
+        // Assuming the the map will always be asked for after the source
+        // code.
+        const { sourceMap } = this._lastModule;
+        this._lastModule = undefined;
+        return sourceMap;
+      } else {
+        // Errors thrown here are caught by source-map.
+        throw new Error(`Unable to find source map: "${fileName}"`);
+      }
+    }
+  };
+
   /** For a given module specifier and containing file, return a list of
    * absolute identifiers for dependent modules that are required by this
    * module.
@@ -586,7 +571,8 @@ export class DenoCompiler
       mediaType = fetchResponse.mediaType;
       sourceCode = fetchResponse.sourceCode;
       outputCode = fetchResponse.outputCode;
-      sourceMap = fetchResponse.sourceMap;
+      sourceMap =
+        fetchResponse.sourceMap && JSON.parse(fetchResponse.sourceMap);
     }
     assert(moduleId != null, "No module ID.");
     assert(fileName != null, "No file name.");

js/compiler_test.ts

@@ -438,7 +438,7 @@ test(function compilerRun() {
   assert(moduleMetaData.hasRun);
   assertEqual(moduleMetaData.sourceCode, fooBarTsSource);
   assertEqual(moduleMetaData.outputCode, fooBarTsOutput);
-  assertEqual(moduleMetaData.sourceMap, fooBarTsSourcemap);
+  assertEqual(JSON.stringify(moduleMetaData.sourceMap), fooBarTsSourcemap);
   assertEqual(moduleMetaData.exports, { foo: "bar" });
 
   assertEqual(
@@ -550,7 +550,7 @@ test(function compilerResolveModule() {
   );
   assertEqual(moduleMetaData.sourceCode, fooBazTsSource);
   assertEqual(moduleMetaData.outputCode, fooBazTsOutput);
-  assertEqual(moduleMetaData.sourceMap, fooBazTsSourcemap);
+  assertEqual(JSON.stringify(moduleMetaData.sourceMap), fooBazTsSourcemap);
   assert(!moduleMetaData.hasRun);
   assert(!moduleMetaData.deps);
   assertEqual(moduleMetaData.exports, {});

js/main.ts

@@ -9,11 +9,19 @@ import { args } from "./deno";
 import { sendSync, handleAsyncMsgFromRust } from "./dispatch";
 import { promiseErrorExaminer, promiseRejectHandler } from "./promise_util";
 import { replLoop } from "./repl";
+import * as sourceMaps from "./v8_source_maps";
 import { version } from "typescript";
 
-// Instantiate compiler at the top-level so it decodes source maps for the main
-// bundle during snapshot.
+// Install the source maps handler and do some pre-calculations so all of it is
+// available in the snapshot
 const compiler = DenoCompiler.instance();
+sourceMaps.install({
+  installPrepareStackTrace: true,
+  getGeneratedContents: compiler.getGeneratedContents
+});
+const consumer = sourceMaps.loadConsumer("gen/bundle/main.js");
+assert(consumer != null);
+consumer!.computeColumnSpans();
 
 function sendStart(): msg.StartRes {
   const builder = flatbuffers.createBuilder();

js/v8_source_maps.ts

@@ -3,9 +3,8 @@
 // Originated from source-map-support but has been heavily modified for deno.
 
 import { SourceMapConsumer, MappedPosition } from "source-map";
-import * as base64 from "base64-js";
-import { arrayToStr } from "./util";
 import { CallSite, RawSourceMap } from "./types";
+import { atob } from "./text_encoding";
 
 const consumers = new Map<string, SourceMapConsumer>();
 
@@ -53,9 +52,9 @@ export function prepareStackTraceWrapper(
 // @internal
 export function prepareStackTrace(error: Error, stack: CallSite[]): string {
   const frames = stack.map(
-    (frame: CallSite) => `\n    at ${wrapCallSite(frame).toString()}`
+    frame => `\n    at ${wrapCallSite(frame).toString()}`
   );
-  return error.toString() + frames.join("");
+  return `${error.toString()}${frames.join("")}`;
 }
 
 // @internal
@@ -74,11 +73,13 @@ export function wrapCallSite(frame: CallSite): CallSite {
     const column = (frame.getColumnNumber() || 1) - 1;
     const position = mapSourcePosition({ source, line, column });
     frame = cloneCallSite(frame);
-    frame.getFileName = () => position.source;
-    frame.getLineNumber = () => position.line;
-    frame.getColumnNumber = () => Number(position.column) + 1;
-    frame.getScriptNameOrSourceURL = () => position.source;
-    frame.toString = () => CallSiteToString(frame);
+    Object.assign(frame, {
+      getFileName: () => position.source,
+      getLineNumber: () => position.line,
+      getColumnNumber: () => Number(position.column) + 1,
+      getScriptNameOrSourceURL: () => position.source,
+      toString: () => CallSiteToString(frame)
+    });
     return frame;
   }
 
@@ -87,8 +88,10 @@ export function wrapCallSite(frame: CallSite): CallSite {
   if (origin) {
     origin = mapEvalOrigin(origin);
     frame = cloneCallSite(frame);
-    frame.getEvalOrigin = () => origin;
-    frame.toString = () => CallSiteToString(frame);
+    Object.assign(frame, {
+      getEvalOrigin: () => origin,
+      toString: () => CallSiteToString(frame)
+    });
     return frame;
   }
 
@@ -96,29 +99,30 @@ export function wrapCallSite(frame: CallSite): CallSite {
   return frame;
 }
 
-function cloneCallSite(frame: CallSite): CallSite {
-  // tslint:disable:no-any
-  const obj: any = {};
-  const frame_ = frame as any;
-  const props = Object.getOwnPropertyNames(Object.getPrototypeOf(frame));
-  props.forEach(name => {
+function cloneCallSite(
+  frame: CallSite
+  // mixin: Partial<CallSite> & { toString: () => string }
+): CallSite {
+  const obj = {} as CallSite;
+  const props = Object.getOwnPropertyNames(
+    Object.getPrototypeOf(frame)
+  ) as Array<keyof CallSite>;
+  for (const name of props) {
     obj[name] = /^(?:is|get)/.test(name)
-      ? () => frame_[name].call(frame)
-      : frame_[name];
-  });
-  return (obj as any) as CallSite;
-  // tslint:enable:no-any
+      ? () => frame[name].call(frame)
+      : frame[name];
+  }
+  return obj;
 }
 
 // Taken from source-map-support, original copied from V8's messages.js
 // MIT License. Copyright (c) 2014 Evan Wallace
 function CallSiteToString(frame: CallSite): string {
-  let fileName;
   let fileLocation = "";
   if (frame.isNative()) {
     fileLocation = "native";
   } else {
-    fileName = frame.getScriptNameOrSourceURL();
+    const fileName = frame.getScriptNameOrSourceURL();
     if (!fileName && frame.isEval()) {
       fileLocation = frame.getEvalOrigin() || "";
       fileLocation += ", "; // Expecting source position to follow.
@@ -134,10 +138,10 @@ function CallSiteToString(frame: CallSite): string {
     }
     const lineNumber = frame.getLineNumber();
     if (lineNumber != null) {
-      fileLocation += ":" + String(lineNumber);
+      fileLocation += `:${lineNumber}`;
       const columnNumber = frame.getColumnNumber();
       if (columnNumber) {
-        fileLocation += ":" + String(columnNumber);
+        fileLocation += `:${columnNumber}`;
       }
     }
   }
@@ -156,7 +160,7 @@ function CallSiteToString(frame: CallSite): string {
     const methodName = frame.getMethodName();
     if (functionName) {
       if (typeName && functionName.indexOf(typeName) !== 0) {
-        line += typeName + ".";
+        line += `${typeName}.`;
       }
       line += functionName;
       if (
@@ -206,8 +210,7 @@ export function loadConsumer(source: string): SourceMapConsumer | null {
     if (reSourceMap.test(sourceMappingURL)) {
       // Support source map URL as a data url
       const rawData = sourceMappingURL.slice(sourceMappingURL.indexOf(",") + 1);
-      const ui8 = base64.toByteArray(rawData);
-      sourceMapData = arrayToStr(ui8);
+      sourceMapData = atob(rawData);
       sourceMappingURL = source;
     } else {
       // TODO Support source map URLs relative to the source URL
@@ -217,7 +220,7 @@ export function loadConsumer(source: string): SourceMapConsumer | null {
 
     const rawSourceMap =
       typeof sourceMapData === "string"
-        ? JSON.parse(sourceMapData)
+        ? (JSON.parse(sourceMapData) as RawSourceMap)
         : sourceMapData;
     consumer = new SourceMapConsumer(rawSourceMap);
     consumers.set(source, consumer);
@@ -225,14 +228,14 @@ export function loadConsumer(source: string): SourceMapConsumer | null {
   return consumer;
 }
 
+// tslint:disable-next-line:max-line-length
+const sourceMapUrlRe = /(?:\/\/[@#][ \t]+sourceMappingURL=([^\s'"]+?)[ \t]*$)|(?:\/\*[@#][ \t]+sourceMappingURL=([^\*]+?)[ \t]*(?:\*\/)[ \t]*$)/gm;
+
 function retrieveSourceMapURL(fileData: string): string | null {
-  // Get the URL of the source map
-  // tslint:disable-next-line:max-line-length
-  const re = /(?:\/\/[@#][ \t]+sourceMappingURL=([^\s'"]+?)[ \t]*$)|(?:\/\*[@#][ \t]+sourceMappingURL=([^\*]+?)[ \t]*(?:\*\/)[ \t]*$)/gm;
   // Keep executing the search to find the *last* sourceMappingURL to avoid
   // picking up sourceMappingURLs from comments, strings, etc.
   let lastMatch, match;
-  while ((match = re.exec(fileData))) {
+  while ((match = sourceMapUrlRe.exec(fileData))) {
     lastMatch = match;
   }
   if (!lastMatch) {
@@ -249,11 +252,14 @@ export function mapSourcePosition(position: Position): MappedPosition {
   return consumer.originalPositionFor(position);
 }
 
+const stackEvalRe = /^eval at ([^(]+) \((.+):(\d+):(\d+)\)$/;
+const nestedEvalRe = /^eval at ([^(]+) \((.+)\)$/;
+
 // Parses code generated by FormatEvalOrigin(), a function inside V8:
 // https://code.google.com/p/v8/source/browse/trunk/src/messages.js
 function mapEvalOrigin(origin: string): string {
   // Most eval() calls are in this format
-  let match = /^eval at ([^(]+) \((.+):(\d+):(\d+)\)$/.exec(origin);
+  let match = stackEvalRe.exec(origin);
   if (match) {
     const position = mapSourcePosition({
       source: match[2],
@@ -269,7 +275,7 @@ function mapEvalOrigin(origin: string): string {
   }
 
   // Parse nested eval() calls using recursion
-  match = /^eval at ([^(]+) \((.+)\)$/.exec(origin);
+  match = nestedEvalRe.exec(origin);
   if (match) {
     return `eval at ${match[1]} (${mapEvalOrigin(match[2])})`;
   }