From d656e6e880fa60753a6dc558f0fd01a04830fe95 Mon Sep 17 00:00:00 2001
From: Louis Ye <yelouis@google.com>
Date: Wed, 16 Jun 2021 11:21:12 -0400
Subject: [PATCH 1/5] fix: Add debugging information for sourcemapper

---
 src/agent/debuglet.ts                     |  3 +-
 src/agent/io/sourcemapper.ts              | 43 +++++++++++++++------
 test/test-circular.ts                     |  2 +-
 test/test-duplicate-expressions.ts        |  2 +-
 test/test-duplicate-nested-expressions.ts |  2 +-
 test/test-evaluated-expressions.ts        |  2 +-
 test/test-expression-side-effect.ts       |  2 +-
 test/test-fat-arrow.ts                    |  2 +-
 test/test-max-data-size.ts                |  2 +-
 test/test-sourcemapper.ts                 | 46 +++++++++++++++++++----
 test/test-this-context.ts                 |  2 +-
 test/test-try-catch.ts                    |  2 +-
 test/test-v8debugapi.ts                   |  6 +--
 13 files changed, 84 insertions(+), 32 deletions(-)

diff --git a/src/agent/debuglet.ts b/src/agent/debuglet.ts
index 691b58fe..da3ca1ec 100644
--- a/src/agent/debuglet.ts
+++ b/src/agent/debuglet.ts
@@ -396,12 +396,13 @@ export class Debuglet extends EventEmitter {
 
     let mapper;
     try {
-      mapper = await SourceMapper.create(findResults.mapFiles);
+      mapper = await SourceMapper.create(findResults.mapFiles, that.logger);
     } catch (err3) {
       that.logger.error('Error processing the sourcemaps.', err3);
       that.emit('initError', err3);
       return;
     }
+
     that.v8debug = debugapi.create(
       that.logger,
       that.config,
diff --git a/src/agent/io/sourcemapper.ts b/src/agent/io/sourcemapper.ts
index df58aec4..92319656 100644
--- a/src/agent/io/sourcemapper.ts
+++ b/src/agent/io/sourcemapper.ts
@@ -18,6 +18,7 @@ import * as path from 'path';
 import {promisify} from 'util';
 import * as sourceMap from 'source-map';
 
+import {Logger} from '../config';
 import {findScriptsFuzzy} from '../util/utils';
 
 const CONCURRENCY = 10;
@@ -167,17 +168,10 @@ async function processSourcemap(
 }
 
 export class SourceMapper {
+  /** Maps each original source path to the corresponding source map info. */
   infoMap: Map<string, MapInfoInput>;
 
-  /**
-   * @param {Array.<string>} sourcemapPaths An array of paths to .map sourcemap
-   *  files that should be processed.  The paths should be relative to the
-   *  current process's current working directory
-   * @param {Logger} logger A logger that reports errors that occurred while
-   *  processing the given sourcemap files
-   * @constructor
-   */
-  constructor() {
+  constructor(readonly logger: Logger) {
     this.infoMap = new Map();
   }
 
@@ -211,6 +205,8 @@ export class SourceMapper {
       Array.from(this.infoMap.keys())
     );
 
+    this.logger.debug(`sourcemapper fuzzy matches: ${matches}`);
+
     if (matches.length === 1) {
       return this.infoMap.get(matches[0]) as MapInfoInput;
     }
@@ -246,6 +242,8 @@ export class SourceMapper {
     colNumber: number,
     entry: MapInfoInput
   ): MapInfoOutput | null {
+    this.logger.debug(`sourcemapper inputPath: ${inputPath}`);
+
     inputPath = path.normalize(inputPath);
 
     const relPath = path
@@ -273,6 +271,8 @@ export class SourceMapper {
       column: colNumber, // to be zero-based
     };
 
+    this.logger.debug(`sourcemapper sourcePos: ${JSON.stringify(sourcePos)}`);
+
     const allPos = entry.mapConsumer.allGeneratedPositionsFor(sourcePos);
     /*
      * Based on testing, it appears that the following code is needed to
@@ -290,6 +290,8 @@ export class SourceMapper {
           })
         : entry.mapConsumer.generatedPositionFor(sourcePos);
 
+    this.logger.debug(`sourcemapper mappedPos: ${JSON.stringify(mappedPos)}`);
+
     return {
       file: entry.outputFile,
       line: (mappedPos.line ?? 0) - 1, // convert the one-based line numbers returned
@@ -305,11 +307,29 @@ export class SourceMapper {
       // output
     };
   }
+
+  /** Prints the debugging information of the source mapper to the logger. */
+  debug() {
+    this.logger.debug('Printing source mapper debugging information ...');
+    for (const [key, value] of this.infoMap) {
+      this.logger.debug(`  source ${key}:`);
+      this.logger.debug(`    outputFile: ${value.outputFile}`);
+      this.logger.debug(`    mapFile: ${value.mapFile}`);
+      this.logger.debug(`    sources: ${value.sources}`);
+    }
+  }
 }
 
-export async function create(sourcemapPaths: string[]): Promise<SourceMapper> {
+/**
+ * @param {Array.<string>} sourcemapPaths An array of paths to .map sourcemap
+ *  files that should be processed.  The paths should be relative to the
+ *  current process's current working directory
+ * @param {Logger} logger A logger that reports errors that occurred while
+ *  processing the given sourcemap files
+ */
+export async function create(sourcemapPaths: string[], logger: Logger): Promise<SourceMapper> {
   const limit = pLimit(CONCURRENCY);
-  const mapper = new SourceMapper();
+  const mapper = new SourceMapper(logger);
   const promises = sourcemapPaths.map(path =>
     limit(() => processSourcemap(mapper.infoMap, path))
   );
@@ -320,5 +340,6 @@ export async function create(sourcemapPaths: string[]): Promise<SourceMapper> {
       'An error occurred while processing the sourcemap files' + err
     );
   }
+  mapper.debug();
   return mapper;
 }
diff --git a/test/test-circular.ts b/test/test-circular.ts
index a6bcb93f..2717cacc 100644
--- a/test/test-circular.ts
+++ b/test/test-circular.ts
@@ -71,7 +71,7 @@ maybeDescribe(__filename, () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         api = debugapi.create(
           logger,
           config,
diff --git a/test/test-duplicate-expressions.ts b/test/test-duplicate-expressions.ts
index 7423473d..a88aa2b2 100644
--- a/test/test-duplicate-expressions.ts
+++ b/test/test-duplicate-expressions.ts
@@ -63,7 +63,7 @@ describe(__filename, () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO: Handle the case when mapper is undefined
         // TODO: Handle the case when v8debugapi.create returns null
         api = debugapi.create(
diff --git a/test/test-duplicate-nested-expressions.ts b/test/test-duplicate-nested-expressions.ts
index 978475df..99f20906 100644
--- a/test/test-duplicate-nested-expressions.ts
+++ b/test/test-duplicate-nested-expressions.ts
@@ -58,7 +58,7 @@ describe(__filename, () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO: Handle the case when mapper is undefined
         // TODO: Handle the case when v8debugapi.create returns null
         api = debugapi.create(
diff --git a/test/test-evaluated-expressions.ts b/test/test-evaluated-expressions.ts
index 40b8e96e..b6fe07ee 100644
--- a/test/test-evaluated-expressions.ts
+++ b/test/test-evaluated-expressions.ts
@@ -41,7 +41,7 @@ describe('debugger provides useful information', () => {
     scanner.scan(config.workingDirectory, /\.js$/).then(async fileStats => {
       const jsStats = fileStats.selectStats(/\.js$/);
       const mapFiles = fileStats.selectFiles(/\.map$/, process.cwd());
-      const mapper = await SourceMapper.create(mapFiles);
+      const mapper = await SourceMapper.create(mapFiles, logger);
       assert(mapper);
       api = debugapi.create(logger, config, jsStats, mapper!);
       done();
diff --git a/test/test-expression-side-effect.ts b/test/test-expression-side-effect.ts
index efb0ffb2..7c6abe3b 100644
--- a/test/test-expression-side-effect.ts
+++ b/test/test-expression-side-effect.ts
@@ -43,7 +43,7 @@ describe('evaluating expressions', () => {
     scanner.scan(config.workingDirectory, /\.js$/).then(async fileStats => {
       const jsStats = fileStats.selectStats(/\.js$/);
       const mapFiles = fileStats.selectFiles(/\.map$/, process.cwd());
-      const mapper = await SourceMapper.create(mapFiles);
+      const mapper = await SourceMapper.create(mapFiles, logger);
       assert(mapper);
       api = debugapi.create(logger, config, jsStats, mapper!);
       done();
diff --git a/test/test-fat-arrow.ts b/test/test-fat-arrow.ts
index 3e97e074..c8786406 100644
--- a/test/test-fat-arrow.ts
+++ b/test/test-fat-arrow.ts
@@ -60,7 +60,7 @@ describe(__filename, () => {
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
         // TODO: Determine if the err parameter should be used.
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO: Handle the case when mapper is undefined
         // TODO: Handle the case when v8debugapi.create returns null
         api = debugapi.create(
diff --git a/test/test-max-data-size.ts b/test/test-max-data-size.ts
index 2d105ba1..f622930d 100644
--- a/test/test-max-data-size.ts
+++ b/test/test-max-data-size.ts
@@ -47,7 +47,7 @@ describe('maxDataSize', () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO: Handle the case when mapper is undefined
         // TODO: Handle the case when v8debugapi.create returns null
         api = debugapi.create(
diff --git a/test/test-sourcemapper.ts b/test/test-sourcemapper.ts
index 0fdf738d..cf800a69 100644
--- a/test/test-sourcemapper.ts
+++ b/test/test-sourcemapper.ts
@@ -20,6 +20,8 @@ import * as path from 'path';
 
 import * as sm from '../src/agent/io/sourcemapper';
 
+import {MockLogger} from './mock-logger';
+
 const BASE_PATH = path.join(__dirname, 'fixtures', 'sourcemapper');
 const QUICK_MILLISECONDS = 300;
 
@@ -52,16 +54,28 @@ function testTool(
   const outputFilePath = path.join(BASE_PATH, relativeOutputFilePath);
 
   describe('sourcemapper for tool ' + tool, () => {
+    const logger = new MockLogger();
     let sourcemapper: sm.SourceMapper;
 
-    it('for tool ' + tool, async () => {
-      const start = Date.now();
-      sourcemapper = await sm.create([mapFilePath]);
-      assert(
-        Date.now() - start < QUICK_MILLISECONDS,
-        'should create the SourceMapper quickly'
-      );
-    });
+    it('for tool ' + tool + ' sourcemapper should be created correctly',
+       async () => {
+         const start = Date.now();
+         sourcemapper = await sm.create([mapFilePath], logger);
+         assert(
+             Date.now() - start < QUICK_MILLISECONDS,
+             'should create the SourceMapper quickly');
+
+         // Verify if the debugging information is correctly printed.
+         assert.notStrictEqual(
+             logger.debugs[0].args[0].indexOf('debugging information ...'), -1);
+         assert.notStrictEqual(logger.debugs[1].args[0].indexOf('source '), -1);
+         assert.notStrictEqual(
+             logger.debugs[2].args[0].indexOf('outputFile'), -1);
+         assert.notStrictEqual(logger.debugs[3].args[0].indexOf('mapFile'), -1);
+         assert.notStrictEqual(logger.debugs[4].args[0].indexOf('sources'), -1);
+         assert.strictEqual(
+             logger.debugs.length, sourcemapper.infoMap.size * 4 + 1);
+       });
 
     it(
       'for tool ' +
@@ -125,6 +139,22 @@ function testTool(
         0,
         mapInfoInput!
       );
+
+      // Verify if the debugging information is correctly printed.
+      const debugsLength = logger.debugs.length;
+      assert.notStrictEqual(
+          logger.debugs[debugsLength - 3].args[0].indexOf(
+              'sourcemapper inputPath:'),
+          -1);
+      assert.notStrictEqual(
+          logger.debugs[debugsLength - 2].args[0].indexOf(
+              'sourcemapper sourcePos: {'),
+          -1);
+      assert.notStrictEqual(
+          logger.debugs[debugsLength - 1].args[0].indexOf(
+              'sourcemapper mappedPos: {'),
+          -1);
+
       assert.notStrictEqual(
         info,
         null,
diff --git a/test/test-this-context.ts b/test/test-this-context.ts
index ea49e2b0..a9991352 100644
--- a/test/test-this-context.ts
+++ b/test/test-this-context.ts
@@ -58,7 +58,7 @@ describe(__filename, () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO: Handle the case when mapper is undefined
         // TODO: Handle the case when v8debugapi.create returns null
         api = debugapi.create(
diff --git a/test/test-try-catch.ts b/test/test-try-catch.ts
index 053ffbd8..d17495d5 100644
--- a/test/test-try-catch.ts
+++ b/test/test-try-catch.ts
@@ -57,7 +57,7 @@ describe(__filename, () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO: Handle the case when mapper is undefined
         // TODO: Handle the case when v8debugapi.create returns null
         api = debugapi.create(
diff --git a/test/test-v8debugapi.ts b/test/test-v8debugapi.ts
index 54a8a35a..ce119775 100644
--- a/test/test-v8debugapi.ts
+++ b/test/test-v8debugapi.ts
@@ -178,7 +178,7 @@ describe('debugapi selection', () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.js.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         // TODO(dominickramer): Handle the case when mapper is undefined.
         // TODO(dominickramer): Handle the case when v8debugapi.create
         // returns null
@@ -222,7 +222,7 @@ describeFn('debugapi selection on Node >=10', () => {
         assert.strictEqual(fileStats.errors().size, 0);
         const jsStats = fileStats.selectStats(/.js$/);
         const mapFiles = fileStats.selectFiles(/.js.map$/, process.cwd());
-        const mapper = await SourceMapper.create(mapFiles);
+        const mapper = await SourceMapper.create(mapFiles, logger);
         assert(mapper);
         api = debugapi.create(logger, config, jsStats, mapper!);
         // eslint-disable-next-line @typescript-eslint/no-var-requires
@@ -250,7 +250,7 @@ describe('v8debugapi', () => {
           assert.strictEqual(fileStats.errors().size, 0);
           const jsStats = fileStats.selectStats(/.js$|.jsz$/);
           const mapFiles = fileStats.selectFiles(/.js.map$/, process.cwd());
-          const mapper = await SourceMapper.create(mapFiles);
+          const mapper = await SourceMapper.create(mapFiles, logger);
 
           // TODO(dominickramer): Handle the case when mapper is undefined.
           // TODO(dominickramer): Handle the case when v8debugapi.create

From 410e8eb9084a72203e63fb5df8d43adc8d183c54 Mon Sep 17 00:00:00 2001
From: Louis Ye <yelouis@google.com>
Date: Wed, 16 Jun 2021 11:42:28 -0400
Subject: [PATCH 2/5] Fix lint issue

---
 src/agent/io/sourcemapper.ts |  5 ++-
 test/test-sourcemapper.ts    | 69 ++++++++++++++++++++++--------------
 2 files changed, 46 insertions(+), 28 deletions(-)

diff --git a/src/agent/io/sourcemapper.ts b/src/agent/io/sourcemapper.ts
index 92319656..3be5316a 100644
--- a/src/agent/io/sourcemapper.ts
+++ b/src/agent/io/sourcemapper.ts
@@ -327,7 +327,10 @@ export class SourceMapper {
  * @param {Logger} logger A logger that reports errors that occurred while
  *  processing the given sourcemap files
  */
-export async function create(sourcemapPaths: string[], logger: Logger): Promise<SourceMapper> {
+export async function create(
+  sourcemapPaths: string[],
+  logger: Logger
+): Promise<SourceMapper> {
   const limit = pLimit(CONCURRENCY);
   const mapper = new SourceMapper(logger);
   const promises = sourcemapPaths.map(path =>
diff --git a/test/test-sourcemapper.ts b/test/test-sourcemapper.ts
index cf800a69..56e517cd 100644
--- a/test/test-sourcemapper.ts
+++ b/test/test-sourcemapper.ts
@@ -57,25 +57,34 @@ function testTool(
     const logger = new MockLogger();
     let sourcemapper: sm.SourceMapper;
 
-    it('for tool ' + tool + ' sourcemapper should be created correctly',
-       async () => {
-         const start = Date.now();
-         sourcemapper = await sm.create([mapFilePath], logger);
-         assert(
-             Date.now() - start < QUICK_MILLISECONDS,
-             'should create the SourceMapper quickly');
+    it(
+      'for tool ' + tool + ' sourcemapper should be created correctly',
+      async () => {
+        const start = Date.now();
+        sourcemapper = await sm.create([mapFilePath], logger);
+        assert(
+          Date.now() - start < QUICK_MILLISECONDS,
+          'should create the SourceMapper quickly'
+        );
 
-         // Verify if the debugging information is correctly printed.
-         assert.notStrictEqual(
-             logger.debugs[0].args[0].indexOf('debugging information ...'), -1);
-         assert.notStrictEqual(logger.debugs[1].args[0].indexOf('source '), -1);
-         assert.notStrictEqual(
-             logger.debugs[2].args[0].indexOf('outputFile'), -1);
-         assert.notStrictEqual(logger.debugs[3].args[0].indexOf('mapFile'), -1);
-         assert.notStrictEqual(logger.debugs[4].args[0].indexOf('sources'), -1);
-         assert.strictEqual(
-             logger.debugs.length, sourcemapper.infoMap.size * 4 + 1);
-       });
+        // Verify if the debugging information is correctly printed.
+        assert.notStrictEqual(
+          logger.debugs[0].args[0].indexOf('debugging information ...'),
+          -1
+        );
+        assert.notStrictEqual(logger.debugs[1].args[0].indexOf('source '), -1);
+        assert.notStrictEqual(
+          logger.debugs[2].args[0].indexOf('outputFile'),
+          -1
+        );
+        assert.notStrictEqual(logger.debugs[3].args[0].indexOf('mapFile'), -1);
+        assert.notStrictEqual(logger.debugs[4].args[0].indexOf('sources'), -1);
+        assert.strictEqual(
+          logger.debugs.length,
+          sourcemapper.infoMap.size * 4 + 1
+        );
+      }
+    );
 
     it(
       'for tool ' +
@@ -143,17 +152,23 @@ function testTool(
       // Verify if the debugging information is correctly printed.
       const debugsLength = logger.debugs.length;
       assert.notStrictEqual(
-          logger.debugs[debugsLength - 3].args[0].indexOf(
-              'sourcemapper inputPath:'),
-          -1);
+        logger.debugs[debugsLength - 3].args[0].indexOf(
+          'sourcemapper inputPath:'
+        ),
+        -1
+      );
       assert.notStrictEqual(
-          logger.debugs[debugsLength - 2].args[0].indexOf(
-              'sourcemapper sourcePos: {'),
-          -1);
+        logger.debugs[debugsLength - 2].args[0].indexOf(
+          'sourcemapper sourcePos: {'
+        ),
+        -1
+      );
       assert.notStrictEqual(
-          logger.debugs[debugsLength - 1].args[0].indexOf(
-              'sourcemapper mappedPos: {'),
-          -1);
+        logger.debugs[debugsLength - 1].args[0].indexOf(
+          'sourcemapper mappedPos: {'
+        ),
+        -1
+      );
 
       assert.notStrictEqual(
         info,

From d478a120714ff41190e6ad2ad0386e3cc7aa939e Mon Sep 17 00:00:00 2001
From: Louis Ye <yelouis@google.com>
Date: Fri, 18 Jun 2021 10:46:53 -0400
Subject: [PATCH 3/5] Separate the debugging info related test cases in
 sourcemapper

---
 src/agent/config.ts                |   8 +-
 src/agent/v8/inspector-debugapi.ts | 130 +++++++++++++++++++++-------
 src/agent/v8/v8inspector.ts        | 134 +++--------------------------
 test/test-sourcemapper.ts          | 133 +++++++++++++++++-----------
 test/test-v8debugapi.ts            |  46 +---------
 5 files changed, 203 insertions(+), 248 deletions(-)

diff --git a/src/agent/config.ts b/src/agent/config.ts
index 6b325a14..45ef4f36 100644
--- a/src/agent/config.ts
+++ b/src/agent/config.ts
@@ -359,10 +359,10 @@ export interface ResolvedDebugAgentConfig extends GoogleAuthOptions {
   apiUrl?: string;
 
   /**
-   * Number of times the V8 pauses (could be breakpoint hits) before the
-   * debugging session is reset. This is to release the memory usage held by V8
-   * engine for each breakpoint hit to prevent the memory leak. The default
-   * value is specified in defaultConfig.
+   * Number of times of the V8 breakpoint hits events before resetting the
+   * breakpoints. This is to release the memory usage held by V8 engine for each
+   * breakpoint hit to prevent the memory leak. The default value is specified
+   * in defaultConfig.
    */
   resetV8DebuggerThreshold: number;
 }
diff --git a/src/agent/v8/inspector-debugapi.ts b/src/agent/v8/inspector-debugapi.ts
index c47522fb..8e1b4807 100644
--- a/src/agent/v8/inspector-debugapi.ts
+++ b/src/agent/v8/inspector-debugapi.ts
@@ -34,6 +34,32 @@ import * as utils from '../util/utils';
 import * as debugapi from './debugapi';
 import {V8Inspector} from './v8inspector';
 
+/**
+ * An interface that describes options that set behavior when interacting with
+ * the V8 Inspector API.
+ */
+interface InspectorOptions {
+  /**
+   * Whether to add a 'file://' prefix to a URL when setting breakpoints.
+   */
+  useWellFormattedUrl: boolean;
+}
+
+/** Data related to the v8 inspector. */
+interface V8Data {
+  session: inspector.Session;
+  // Options for behavior when interfacing with the Inspector API.
+  inspectorOptions: InspectorOptions;
+  inspector: V8Inspector;
+  // Store the v8 setBreakpoint parameters for each v8 breakpoint so that later
+  // the recorded parameters can be used to reset the breakpoints.
+  setBreakpointsParams: {
+    [
+      v8BreakpointId: string
+    ]: inspector.Debugger.SetBreakpointByUrlParameterType;
+  };
+}
+
 /**
  * In older versions of Node, the script source as seen by the Inspector
  * backend is wrapped in `require('module').wrapper`, and in new versions
@@ -73,9 +99,8 @@ export class InspectorDebugApi implements debugapi.DebugApi {
   // stackdriver breakpoint id.
   breakpointMapper: {[id: string]: stackdriver.BreakpointId[]} = {};
   numBreakpoints = 0;
-
-  // The wrapper class that interacts with the V8 debugger.
-  inspector: V8Inspector;
+  numBreakpointHitsBeforeReset = 0;
+  v8: V8Data;
 
   constructor(
     logger: consoleLogLevel.Logger,
@@ -87,28 +112,36 @@ export class InspectorDebugApi implements debugapi.DebugApi {
     this.config = config;
     this.fileStats = jsFiles;
     this.sourcemapper = sourcemapper;
-    this.inspector = new V8Inspector(
-      /* logger=*/ logger,
-      /*useWellFormattedUrl=*/ utils.satisfies(process.version, '>10.11.0'),
-      /*resetV8DebuggerThreshold=*/ this.config.resetV8DebuggerThreshold,
-      /*onScriptParsed=*/
-      scriptParams => {
-        this.scriptMapper[scriptParams.scriptId] = scriptParams;
-      },
-      /*onPaused=*/
-      messageParams => {
-        try {
-          this.handleDebugPausedEvent(messageParams);
-        } catch (error) {
-          this.logger.error(error);
-        }
-      }
-    );
+    this.scriptMapper = {};
+    this.v8 = this.createV8Data();
   }
 
-  /** Disconnects and marks the current V8 data as not connected. */
-  disconnect(): void {
-    this.inspector.detach();
+  /** Creates a new V8 Debugging session and the related data. */
+  private createV8Data(): V8Data {
+    const session = new inspector.Session();
+    session.connect();
+    session.on('Debugger.scriptParsed', script => {
+      this.scriptMapper[script.params.scriptId] = script.params;
+    });
+    session.post('Debugger.enable');
+    session.post('Debugger.setBreakpointsActive', {active: true});
+    session.on('Debugger.paused', message => {
+      try {
+        this.handleDebugPausedEvent(message.params);
+      } catch (error) {
+        this.logger.error(error);
+      }
+    });
+
+    return {
+      session,
+      inspectorOptions: {
+        // Well-Formatted URL is required in Node 10.11.1+.
+        useWellFormattedUrl: utils.satisfies(process.version, '>10.11.0'),
+      },
+      inspector: new V8Inspector(session),
+      setBreakpointsParams: {},
+    };
   }
 
   set(
@@ -235,7 +268,8 @@ export class InspectorDebugApi implements debugapi.DebugApi {
     if (!this.breakpointMapper[breakpointData.id]) {
       // When breakpointmapper does not countain current v8/inspector breakpoint
       // id, we should remove this breakpoint from v8.
-      result = this.inspector.removeBreakpoint(breakpointData.id);
+      result = this.v8.inspector.removeBreakpoint(breakpointData.id);
+      delete this.v8.setBreakpointsParams[breakpointData.id];
     }
     delete this.breakpoints[breakpoint.id];
     delete this.listeners[breakpoint.id];
@@ -312,6 +346,10 @@ export class InspectorDebugApi implements debugapi.DebugApi {
     this.listeners[breakpoint.id] = {enabled: true, listener};
   }
 
+  disconnect(): void {
+    this.v8.session.disconnect();
+  }
+
   numBreakpoints_(): number {
     // Tracks the number of stackdriver breakpoints.
     return Object.keys(this.breakpoints).length;
@@ -499,7 +537,7 @@ export class InspectorDebugApi implements debugapi.DebugApi {
     let v8BreakpointId; // v8/inspector breakpoint id
     if (!this.locationMapper[locationStr]) {
       // The first time when a breakpoint was set to this location.
-      const rawUrl = this.inspector.shouldUseWellFormattedUrl()
+      const rawUrl = this.v8.inspectorOptions.useWellFormattedUrl
         ? `file://${matchingScript}`
         : matchingScript;
       // on windows on Node 11+, the url must start with file:///
@@ -508,17 +546,19 @@ export class InspectorDebugApi implements debugapi.DebugApi {
         process.platform === 'win32' && utils.satisfies(process.version, '>=11')
           ? rawUrl.replace(/^file:\/\//, 'file:///').replace(/\\/g, '/')
           : rawUrl;
-      const res = this.inspector.setBreakpointByUrl({
+      const params = {
         lineNumber: line - 1,
         url,
         columnNumber: column - 1,
         condition: breakpoint.condition || undefined,
-      });
+      };
+      const res = this.v8.inspector.setBreakpointByUrl(params);
       if (res.error || !res.response) {
         // Error case.
         return null;
       }
       v8BreakpointId = res.response.breakpointId;
+      this.v8.setBreakpointsParams[v8BreakpointId] = params;
 
       this.locationMapper[locationStr] = [];
       this.breakpointMapper[v8BreakpointId] = [];
@@ -606,7 +646,7 @@ export class InspectorDebugApi implements debugapi.DebugApi {
         const evaluatedExpressions = breakpoint.expressions.map(exp => {
           // returnByValue is set to true here so that the JSON string of the
           // value will be returned to log.
-          const result = state.evaluate(exp, frame, that.inspector, true);
+          const result = state.evaluate(exp, frame, that.v8.inspector, true);
           if (result.error) {
             return result.error;
           } else {
@@ -621,7 +661,7 @@ export class InspectorDebugApi implements debugapi.DebugApi {
         breakpoint,
         this.config,
         this.scriptMapper,
-        this.inspector
+        this.v8.inspector
       );
       if (
         breakpoint.location &&
@@ -655,5 +695,37 @@ export class InspectorDebugApi implements debugapi.DebugApi {
     } catch (e) {
       this.logger.warn('Internal V8 error on breakpoint event: ' + e);
     }
+
+    this.tryResetV8Debugger();
+  }
+
+  /**
+   * Periodically resets breakpoints to prevent memory leaks in V8 (for holding
+   * contexts of previous breakpoint hits).
+   */
+  private tryResetV8Debugger() {
+    this.numBreakpointHitsBeforeReset += 1;
+    if (
+      this.numBreakpointHitsBeforeReset < this.config.resetV8DebuggerThreshold
+    ) {
+      return;
+    }
+    this.numBreakpointHitsBeforeReset = 0;
+
+    const storedParams = this.v8.setBreakpointsParams;
+
+    // Re-connect the session to clean the memory usage.
+    this.disconnect();
+    this.scriptMapper = {};
+    this.v8 = this.createV8Data();
+    this.v8.setBreakpointsParams = storedParams;
+
+    // Setting the v8 breakpoints again according to the stored parameters.
+    for (const params of Object.values(storedParams)) {
+      const res = this.v8.inspector.setBreakpointByUrl(params);
+      if (res.error || !res.response) {
+        this.logger.error('Error upon re-setting breakpoint: ' + res);
+      }
+    }
   }
 }
diff --git a/src/agent/v8/v8inspector.ts b/src/agent/v8/v8inspector.ts
index 0e6e5afb..bc17ec69 100644
--- a/src/agent/v8/v8inspector.ts
+++ b/src/agent/v8/v8inspector.ts
@@ -15,61 +15,26 @@
 // eslint-disable-next-line node/no-unsupported-features/node-builtins
 import * as inspector from 'inspector';
 
-import consoleLogLevel = require('console-log-level');
-
 export class V8Inspector {
-  // The V8 debugger session.
-  session: inspector.Session | null = null;
-
-  // Store of the v8 setBreakpoint parameters for each v8 breakpoint so that
-  // later the recorded parameters can be used to reset the breakpoints.
-  storeSetBreakpointParams: {
-    [
-      v8BreakpointId: string
-    ]: inspector.Debugger.SetBreakpointByUrlParameterType;
-  } = {};
-
-  // Number of paused events before the next reset.
-  numPausedBeforeReset = 0;
-
-  constructor(
-    readonly logger: consoleLogLevel.Logger,
-    readonly useWellFormattedUrl: boolean,
-    readonly resetV8DebuggerThreshold: number,
-    readonly onScriptParsed: (
-      script: inspector.Debugger.ScriptParsedEventDataType
-    ) => void,
-    readonly onPaused: (params: inspector.Debugger.PausedEventDataType) => void
-  ) {}
-
-  /**
-   * Whether to add a 'file://' prefix to a URL when setting breakpoints.
-   */
-  shouldUseWellFormattedUrl() {
-    return this.useWellFormattedUrl;
+  private session: inspector.Session;
+  constructor(session: inspector.Session) {
+    this.session = session;
   }
-
   setBreakpointByUrl(
-    params: inspector.Debugger.SetBreakpointByUrlParameterType
+    options: inspector.Debugger.SetBreakpointByUrlParameterType
   ) {
-    this.attach();
-
     const result: {
       error?: Error;
       response?: inspector.Debugger.SetBreakpointByUrlReturnType;
     } = {};
-    this.session!.post(
+    this.session.post(
       'Debugger.setBreakpointByUrl',
-      params,
+      options,
       (
         error: Error | null,
         response: inspector.Debugger.SetBreakpointByUrlReturnType
       ) => {
-        if (error) {
-          result.error = error;
-        } else {
-          this.storeSetBreakpointParams[response.breakpointId] = params;
-        }
+        if (error) result.error = error;
         result.response = response;
       }
     );
@@ -77,23 +42,12 @@ export class V8Inspector {
   }
 
   removeBreakpoint(breakpointId: string) {
-    this.attach();
-
     const result: {error?: Error} = {};
-    this.session!.post(
+    this.session.post(
       'Debugger.removeBreakpoint',
       {breakpointId},
       (error: Error | null) => {
-        if (error) {
-          result.error = error;
-        } else {
-          delete this.storeSetBreakpointParams[breakpointId];
-        }
-
-        // If there is no active V8 breakpoints, then detach the session.
-        if (Object.keys(this.storeSetBreakpointParams).length === 0) {
-          this.detach();
-        }
+        if (error) result.error = error;
       }
     );
     return result;
@@ -102,13 +56,11 @@ export class V8Inspector {
   evaluateOnCallFrame(
     options: inspector.Debugger.EvaluateOnCallFrameParameterType
   ) {
-    this.attach();
-
     const result: {
       error?: Error;
       response?: inspector.Debugger.EvaluateOnCallFrameReturnType;
     } = {};
-    this.session!.post(
+    this.session.post(
       'Debugger.evaluateOnCallFrame',
       options,
       (
@@ -127,9 +79,7 @@ export class V8Inspector {
       error?: Error;
       response?: inspector.Runtime.GetPropertiesReturnType;
     } = {};
-    this.attach();
-
-    this.session!.post(
+    this.session.post(
       'Runtime.getProperties',
       options,
       (
@@ -142,66 +92,4 @@ export class V8Inspector {
     );
     return result;
   }
-
-  /** Attaches to the V8 debugger. */
-  private attach() {
-    if (this.session) {
-      return;
-    }
-
-    const session = new inspector.Session();
-    session.connect();
-    session.on('Debugger.scriptParsed', script => {
-      this.onScriptParsed(script.params);
-    });
-    session.post('Debugger.enable');
-    session.post('Debugger.setBreakpointsActive', {active: true});
-    session.on('Debugger.paused', message => {
-      this.onPaused(message.params);
-      this.resetV8DebuggerIfThresholdMet();
-    });
-
-    this.session = session;
-  }
-
-  /**
-   * Detaches from the V8 debugger. This will purge all the existing V8
-   * breakpoints from the V8 debugger.
-   */
-  detach() {
-    if (!this.session) {
-      return;
-    }
-
-    this.session!.disconnect();
-    this.session = null;
-    this.storeSetBreakpointParams = {};
-    this.numPausedBeforeReset = 0;
-  }
-
-  /**
-   * Resets the debugging session when the number of paused events meets the
-   * threshold. This is primarily for cleaning the memory usage hold by V8
-   * debugger when hitting the V8 breakpoints too many times.
-   */
-  private resetV8DebuggerIfThresholdMet() {
-    this.numPausedBeforeReset += 1;
-    if (this.numPausedBeforeReset < this.resetV8DebuggerThreshold) {
-      return;
-    }
-    this.numPausedBeforeReset = 0;
-
-    const previouslyStoredParams = this.storeSetBreakpointParams;
-
-    this.detach();
-    this.attach();
-
-    // Setting the v8 breakpoints again according to the stored parameters.
-    for (const params of Object.values(previouslyStoredParams)) {
-      const res = this.setBreakpointByUrl(params);
-      if (res.error || !res.response) {
-        this.logger.error('Error upon re-setting breakpoint: ' + res);
-      }
-    }
-  }
 }
diff --git a/test/test-sourcemapper.ts b/test/test-sourcemapper.ts
index 56e517cd..ce9920b5 100644
--- a/test/test-sourcemapper.ts
+++ b/test/test-sourcemapper.ts
@@ -42,6 +42,81 @@ const QUICK_MILLISECONDS = 300;
  *
  *  Note: The line numbers are zero-based
  */
+
+describe('sourcemapper debug info', () => {
+  const logger = new MockLogger();
+  const mapFilePath = path.join(
+    BASE_PATH,
+    path.join('typescript', 'out.js.map')
+  );
+
+  it('should be printed upon creation', async () => {
+    const sourcemapper = await sm.create([mapFilePath], logger);
+
+    // Verify if the debugging information is correctly printed.
+    assert.notStrictEqual(
+      logger.debugs[0].args[0].match('debugging information ...'),
+      null
+    );
+    assert.notStrictEqual(
+      logger.debugs[1].args[0].match(
+        'test/fixtures/sourcemapper/typescript/in.ts'
+      ),
+      null
+    );
+    assert.notStrictEqual(
+      logger.debugs[2].args[0].match(
+        'test/fixtures/sourcemapper/typescript/out.js'
+      ),
+      null
+    );
+    assert.notStrictEqual(
+      logger.debugs[3].args[0].match(
+        'test/fixtures/sourcemapper/typescript/out.js.map'
+      ),
+      null
+    );
+    assert.notStrictEqual(
+      logger.debugs[4].args[0].match('sources: in.ts'),
+      null
+    );
+    assert.strictEqual(logger.debugs.length, sourcemapper.infoMap.size * 4 + 1);
+  });
+
+  it('should be printed when upon get infomap output', async () => {
+    const sourcemapper = await sm.create([mapFilePath], logger);
+    const inputFilePath = path.join(
+      BASE_PATH,
+      path.join('typescript', 'in.ts')
+    );
+
+    const mapInfoInput = sourcemapper.getMapInfoInput(inputFilePath);
+    assert.notEqual(mapInfoInput, null);
+    sourcemapper.getMapInfoOutput(inputFilePath, 1, 0, mapInfoInput!);
+
+    // Verify if the debugging information is correctly printed.
+    const debugsLength = logger.debugs.length;
+    assert.notStrictEqual(
+      logger.debugs[debugsLength - 3].args[0].indexOf(
+        'sourcemapper inputPath:'
+      ),
+      -1
+    );
+    assert.notStrictEqual(
+      logger.debugs[debugsLength - 2].args[0].indexOf(
+        'sourcemapper sourcePos: {'
+      ),
+      -1
+    );
+    assert.notStrictEqual(
+      logger.debugs[debugsLength - 1].args[0].indexOf(
+        'sourcemapper mappedPos: {'
+      ),
+      -1
+    );
+  });
+});
+
 function testTool(
   tool: string,
   relativeMapFilePath: string,
@@ -57,34 +132,14 @@ function testTool(
     const logger = new MockLogger();
     let sourcemapper: sm.SourceMapper;
 
-    it(
-      'for tool ' + tool + ' sourcemapper should be created correctly',
-      async () => {
-        const start = Date.now();
-        sourcemapper = await sm.create([mapFilePath], logger);
-        assert(
-          Date.now() - start < QUICK_MILLISECONDS,
-          'should create the SourceMapper quickly'
-        );
-
-        // Verify if the debugging information is correctly printed.
-        assert.notStrictEqual(
-          logger.debugs[0].args[0].indexOf('debugging information ...'),
-          -1
-        );
-        assert.notStrictEqual(logger.debugs[1].args[0].indexOf('source '), -1);
-        assert.notStrictEqual(
-          logger.debugs[2].args[0].indexOf('outputFile'),
-          -1
-        );
-        assert.notStrictEqual(logger.debugs[3].args[0].indexOf('mapFile'), -1);
-        assert.notStrictEqual(logger.debugs[4].args[0].indexOf('sources'), -1);
-        assert.strictEqual(
-          logger.debugs.length,
-          sourcemapper.infoMap.size * 4 + 1
-        );
-      }
-    );
+    it('for tool ' + tool, async () => {
+      const start = Date.now();
+      sourcemapper = await sm.create([mapFilePath], logger);
+      assert(
+        Date.now() - start < QUICK_MILLISECONDS,
+        'should create the SourceMapper quickly'
+      );
+    });
 
     it(
       'for tool ' +
@@ -148,28 +203,6 @@ function testTool(
         0,
         mapInfoInput!
       );
-
-      // Verify if the debugging information is correctly printed.
-      const debugsLength = logger.debugs.length;
-      assert.notStrictEqual(
-        logger.debugs[debugsLength - 3].args[0].indexOf(
-          'sourcemapper inputPath:'
-        ),
-        -1
-      );
-      assert.notStrictEqual(
-        logger.debugs[debugsLength - 2].args[0].indexOf(
-          'sourcemapper sourcePos: {'
-        ),
-        -1
-      );
-      assert.notStrictEqual(
-        logger.debugs[debugsLength - 1].args[0].indexOf(
-          'sourcemapper mappedPos: {'
-        ),
-        -1
-      );
-
       assert.notStrictEqual(
         info,
         null,
diff --git a/test/test-v8debugapi.ts b/test/test-v8debugapi.ts
index ce119775..47c26e09 100644
--- a/test/test-v8debugapi.ts
+++ b/test/test-v8debugapi.ts
@@ -766,41 +766,7 @@ describe('v8debugapi', () => {
       assert(stateIsClean(api));
     });
 
-    it('should only attach to v8 when having active breakpoints', done => {
-      // The test is only eligible for the InspectorDebugApi test target.
-      if (!(api instanceof InspectorDebugApi)) {
-        done();
-        return;
-      }
-
-      const inspectorDebugApi = api as InspectorDebugApi;
-      assert.strictEqual(inspectorDebugApi.inspector.session, null);
-
-      const bp: stackdriver.Breakpoint = {
-        id: breakpointInFoo.id,
-        location: breakpointInFoo.location,
-        action: 'LOG',
-        logMessageFormat: 'cat',
-      } as {} as stackdriver.Breakpoint;
-      api.set(bp, err1 => {
-        assert.ifError(err1);
-        api.log(
-          bp,
-          () => {},
-          () => false
-        );
-
-        assert.notStrictEqual(inspectorDebugApi.inspector.session, null);
-
-        api.clear(bp, err2 => {
-          assert.ifError(err2);
-          assert.strictEqual(inspectorDebugApi.inspector.session, null);
-          done();
-        });
-      });
-    });
-
-    it('should reset v8 debugging session when meeting threshold', done => {
+    it('should perform v8 breakpoints reset when meeting threshold', done => {
       // The test is only eligible for the InspectorDebugApi test target.
       if (!(api instanceof InspectorDebugApi)) {
         done();
@@ -826,7 +792,7 @@ describe('v8debugapi', () => {
         );
 
         const inspectorDebugApi = api as InspectorDebugApi;
-        const v8SessionBeforeReset = inspectorDebugApi.inspector.session;
+        const v8BeforeReset = inspectorDebugApi.v8;
 
         // The loop should trigger the breakpoints reset.
         for (let i = 0; i < config.resetV8DebuggerThreshold; i++) {
@@ -834,13 +800,9 @@ describe('v8debugapi', () => {
         }
 
         // Expect the current v8 data is no longer the previous one.
-        assert.notStrictEqual(
-          inspectorDebugApi.inspector.session,
-          v8SessionBeforeReset
-        );
+        assert.notStrictEqual(inspectorDebugApi.v8, v8BeforeReset);
 
-        // Make sure the logpoint is still triggered correctly after the second
-        // reset.
+        // Make sure the logpoint is still triggered correctly after the second reset.
         for (let i = 0; i < config.resetV8DebuggerThreshold + 1; i++) {
           code.foo(1);
         }

From 454bd3b9fe55f646b10561dbb20e3a96522be3f6 Mon Sep 17 00:00:00 2001
From: Louis Ye <yelouis@google.com>
Date: Fri, 18 Jun 2021 10:58:24 -0400
Subject: [PATCH 4/5] Use match instead of indexOf, use normalize for windows
 in tests

---
 test/test-sourcemapper.ts | 55 +++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 31 deletions(-)

diff --git a/test/test-sourcemapper.ts b/test/test-sourcemapper.ts
index ce9920b5..3606ffe1 100644
--- a/test/test-sourcemapper.ts
+++ b/test/test-sourcemapper.ts
@@ -58,28 +58,21 @@ describe('sourcemapper debug info', () => {
       logger.debugs[0].args[0].match('debugging information ...'),
       null
     );
-    assert.notStrictEqual(
-      logger.debugs[1].args[0].match(
-        'test/fixtures/sourcemapper/typescript/in.ts'
-      ),
-      null
-    );
-    assert.notStrictEqual(
-      logger.debugs[2].args[0].match(
-        'test/fixtures/sourcemapper/typescript/out.js'
-      ),
-      null
-    );
-    assert.notStrictEqual(
-      logger.debugs[3].args[0].match(
-        'test/fixtures/sourcemapper/typescript/out.js.map'
-      ),
-      null
-    );
-    assert.notStrictEqual(
-      logger.debugs[4].args[0].match('sources: in.ts'),
-      null
-    );
+    const expectedDebugMessages = [
+      'debugging information ...',
+      path.normalize('test/fixtures/sourcemapper/typescript/in.ts'),
+      path.normalize('test/fixtures/sourcemapper/typescript/out.js'),
+      path.normalize('test/fixtures/sourcemapper/typescript/out.js.map'),
+      'sources: in.ts',
+    ];
+
+    for (let i = 0; i < expectedDebugMessages.length; i++) {
+      assert.notStrictEqual(
+        logger.debugs[i].args[0].match(expectedDebugMessages[i]),
+        null,
+        `'${logger.debugs[i].args[0]}' does not match '${expectedDebugMessages[i]}'`
+      );
+    }
     assert.strictEqual(logger.debugs.length, sourcemapper.infoMap.size * 4 + 1);
   });
 
@@ -97,22 +90,22 @@ describe('sourcemapper debug info', () => {
     // Verify if the debugging information is correctly printed.
     const debugsLength = logger.debugs.length;
     assert.notStrictEqual(
-      logger.debugs[debugsLength - 3].args[0].indexOf(
-        'sourcemapper inputPath:'
+      logger.debugs[debugsLength - 3].args[0].match(
+        `sourcemapper inputPath: ${inputFilePath}`
       ),
-      -1
+      null
     );
     assert.notStrictEqual(
-      logger.debugs[debugsLength - 2].args[0].indexOf(
-        'sourcemapper sourcePos: {'
+      logger.debugs[debugsLength - 2].args[0].match(
+        'sourcePos: {"source":"in.ts","line":2,"column":0}'
       ),
-      -1
+      null
     );
     assert.notStrictEqual(
-      logger.debugs[debugsLength - 1].args[0].indexOf(
-        'sourcemapper mappedPos: {'
+      logger.debugs[debugsLength - 1].args[0].match(
+        'mappedPos: {"line":6,"column":0,"lastColumn":null}'
       ),
-      -1
+      null
     );
   });
 });

From a873a027d263287bee21be7df7a4e9e2e3870138 Mon Sep 17 00:00:00 2001
From: Louis Ye <yelouis@google.com>
Date: Fri, 18 Jun 2021 11:29:53 -0400
Subject: [PATCH 5/5] Use indexof for windows in test

---
 test/test-sourcemapper.ts | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/test/test-sourcemapper.ts b/test/test-sourcemapper.ts
index 3606ffe1..834f4b73 100644
--- a/test/test-sourcemapper.ts
+++ b/test/test-sourcemapper.ts
@@ -54,10 +54,6 @@ describe('sourcemapper debug info', () => {
     const sourcemapper = await sm.create([mapFilePath], logger);
 
     // Verify if the debugging information is correctly printed.
-    assert.notStrictEqual(
-      logger.debugs[0].args[0].match('debugging information ...'),
-      null
-    );
     const expectedDebugMessages = [
       'debugging information ...',
       path.normalize('test/fixtures/sourcemapper/typescript/in.ts'),
@@ -67,9 +63,12 @@ describe('sourcemapper debug info', () => {
     ];
 
     for (let i = 0; i < expectedDebugMessages.length; i++) {
+      // We use 'indexOf' here instead of 'match' to avoid parsing regular
+      // expression, which will confuse the result when having '\' in the path
+      // name on platform like Windows.
       assert.notStrictEqual(
-        logger.debugs[i].args[0].match(expectedDebugMessages[i]),
-        null,
+        logger.debugs[i].args[0].indexOf(expectedDebugMessages[i]),
+        -1,
         `'${logger.debugs[i].args[0]}' does not match '${expectedDebugMessages[i]}'`
       );
     }
@@ -88,24 +87,27 @@ describe('sourcemapper debug info', () => {
     sourcemapper.getMapInfoOutput(inputFilePath, 1, 0, mapInfoInput!);
 
     // Verify if the debugging information is correctly printed.
+    // We use 'indexOf' here instead of 'match' to avoid parsing regular
+    // expression, which will confuse the result when having '\' in the path
+    // name on platform like Windows.
     const debugsLength = logger.debugs.length;
     assert.notStrictEqual(
-      logger.debugs[debugsLength - 3].args[0].match(
+      logger.debugs[debugsLength - 3].args[0].indexOf(
         `sourcemapper inputPath: ${inputFilePath}`
       ),
-      null
+      -1
     );
     assert.notStrictEqual(
-      logger.debugs[debugsLength - 2].args[0].match(
+      logger.debugs[debugsLength - 2].args[0].indexOf(
         'sourcePos: {"source":"in.ts","line":2,"column":0}'
       ),
-      null
+      -1
     );
     assert.notStrictEqual(
-      logger.debugs[debugsLength - 1].args[0].match(
+      logger.debugs[debugsLength - 1].args[0].indexOf(
         'mappedPos: {"line":6,"column":0,"lastColumn":null}'
       ),
-      null
+      -1
     );
   });
 });