lib: add source map support for assert messages

Map source lines in assert messages with cached source maps. PR-URL: #59751 Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>

Author: legendecas

lib/internal/errors/error_source.js

@@ -8,9 +8,15 @@ const {
 const {
  getErrorSourcePositions,
 } = internalBinding('errors');
+const {
+ getSourceMapsSupport,
+ findSourceMap,
+ getSourceLine,
+} = require('internal/source_map/source_map_cache');
 
 /**
- * Get the source location of an error.
+ * Get the source location of an error. If source map is enabled, resolve the source location
+ * based on the source map.
  *
  * The `error.stack` must not have been accessed. The resolution is based on the structured
  * error stack data.
@@ -21,10 +27,35 @@ function getErrorSourceLocation(error) {
  const pos = getErrorSourcePositions(error);
  const {
  sourceLine,
+ scriptResourceName,
+ lineNumber,
  startColumn,
  } = pos;
 
- return { sourceLine, startColumn };
+ // Source map is not enabled. Return the source line directly.
+ if (!getSourceMapsSupport().enabled) {
+ return { sourceLine, startColumn };
+ }
+
+ const sm = findSourceMap(scriptResourceName);
+ if (sm === undefined) {
+ return;
+ }
+ const {
+ originalLine,
+ originalColumn,
+ originalSource,
+ } = sm.findEntry(lineNumber - 1, startColumn);
+ const originalSourceLine = getSourceLine(sm, originalSource, originalLine, originalColumn);
+
+ if (!originalSourceLine) {
+ return;
+ }
+
+ return {
+ sourceLine: originalSourceLine,
+ startColumn: originalColumn,
+ };
 }
 
 const memberAccessTokens = [ '.', '?.', '[', ']' ];
@@ -111,7 +142,8 @@ function getFirstExpression(code, startColumn) {
 }
 
 /**
- * Get the source expression of an error.
+ * Get the source expression of an error. If source map is enabled, resolve the source location
+ * based on the source map.
  *
  * The `error.stack` must not have been accessed, or the source location may be incorrect. The
  * resolution is based on the structured error stack data.

lib/internal/source_map/prepare_stack_trace.js

@@ -1,11 +1,9 @@
 'use strict';
 
 const {
- ArrayPrototypeIndexOf,
  ArrayPrototypeJoin,
  ArrayPrototypeMap,
  ErrorPrototypeToString,
- RegExpPrototypeSymbolSplit,
  SafeStringIterator,
  StringPrototypeRepeat,
  StringPrototypeSlice,
@@ -16,8 +14,7 @@ let debug = require('internal/util/debuglog').debuglog('source_map', (fn) => {
  debug = fn;
 });
 const { getStringWidth } = require('internal/util/inspect');
-const { readFileSync } = require('fs');
-const { findSourceMap } = require('internal/source_map/source_map_cache');
+const { findSourceMap, getSourceLine } = require('internal/source_map/source_map_cache');
 const {
  kIsNodeError,
 } = require('internal/errors');
@@ -155,21 +152,13 @@ function getErrorSource(
  originalLine,
  originalColumn,
 ) {
- const originalSourcePathNoScheme =
- StringPrototypeStartsWith(originalSourcePath, 'file://') ?
- fileURLToPath(originalSourcePath) : originalSourcePath;
- const source = getOriginalSource(
- sourceMap.payload,
- originalSourcePath,
- );
- if (typeof source !== 'string') {
- return;
- }
- const lines = RegExpPrototypeSymbolSplit(/\r?\n/, source, originalLine + 1);
- const line = lines[originalLine];
+ const line = getSourceLine(sourceMap, originalSourcePath, originalLine);
  if (!line) {
  return;
  }
+ const originalSourcePathNoScheme =
+ StringPrototypeStartsWith(originalSourcePath, 'file://') ?
+ fileURLToPath(originalSourcePath) : originalSourcePath;
 
  // Display ^ in appropriate position, regardless of whether tabs or
  // spaces are used:
@@ -182,39 +171,10 @@ function getErrorSource(
  prefix = StringPrototypeSlice(prefix, 0, -1); // The last character is '^'.
 
  const exceptionLine =
- `${originalSourcePathNoScheme}:${originalLine + 1}\n${line}\n${prefix}^\n\n`;
+ `${originalSourcePathNoScheme}:${originalLine + 1}\n${line}\n${prefix}^\n`;
  return exceptionLine;
 }
 
-/**
- * Retrieve the original source code from the source map's `sources` list or disk.
- * @param {import('internal/source_map/source_map').SourceMap.payload} payload
- * @param {string} originalSourcePath - path or url of the original source
- * @returns {string | undefined} - the source content or undefined if file not found
- */
-function getOriginalSource(payload, originalSourcePath) {
- let source;
- // payload.sources has been normalized to be an array of absolute urls.
- const sourceContentIndex =
- ArrayPrototypeIndexOf(payload.sources, originalSourcePath);
- if (payload.sourcesContent?.[sourceContentIndex]) {
- // First we check if the original source content was provided in the
- // source map itself:
- source = payload.sourcesContent[sourceContentIndex];
- } else if (StringPrototypeStartsWith(originalSourcePath, 'file://')) {
- // If no sourcesContent was found, attempt to load the original source
- // from disk:
- debug(`read source of ${originalSourcePath} from filesystem`);
- const originalSourcePathNoScheme = fileURLToPath(originalSourcePath);
- try {
- source = readFileSync(originalSourcePathNoScheme, 'utf8');
- } catch (err) {
- debug(err);
- }
- }
- return source;
-}
-
 /**
  * Retrieve exact line in the original source code from the source map's `sources` list or disk.
  * @param {string} fileName - actual file name

lib/internal/source_map/source_map_cache.js

@@ -1,13 +1,16 @@
 'use strict';
 
 const {
+ ArrayPrototypeIndexOf,
  ArrayPrototypePush,
  JSONParse,
  ObjectFreeze,
  RegExpPrototypeExec,
+ RegExpPrototypeSymbolSplit,
  SafeMap,
  StringPrototypeCodePointAt,
  StringPrototypeSplit,
+ StringPrototypeStartsWith,
 } = primordials;
 
 // See https://tc39.es/ecma426/ for SourceMap V3 specification.
@@ -16,6 +19,7 @@ let debug = require('internal/util/debuglog').debuglog('source_map', (fn) => {
  debug = fn;
 });
 
+const { readFileSync } = require('fs');
 const { validateBoolean, validateObject } = require('internal/validators');
 const {
  setSourceMapsEnabled: setSourceMapsNative,
@@ -277,8 +281,7 @@ function lineLengths(content) {
  */
 function sourceMapFromFile(mapURL) {
  try {
- const fs = require('fs');
- const content = fs.readFileSync(fileURLToPath(mapURL), 'utf8');
+ const content = readFileSync(fileURLToPath(mapURL), 'utf8');
  const data = JSONParse(content);
  return sourcesToAbsolute(mapURL, data);
  } catch (err) {
@@ -400,8 +403,62 @@ function findSourceMap(sourceURL) {
  }
 }
 
+/**
+ * Retrieve the original source code from the source map's `sources` list or disk.
+ * @param {import('internal/source_map/source_map').SourceMap.payload} payload
+ * @param {string} originalSourcePath - path or url of the original source
+ * @returns {string | undefined} - the source content or undefined if file not found
+ */
+function getOriginalSource(payload, originalSourcePath) {
+ let source;
+ // payload.sources has been normalized to be an array of absolute urls.
+ const sourceContentIndex =
+ ArrayPrototypeIndexOf(payload.sources, originalSourcePath);
+ if (payload.sourcesContent?.[sourceContentIndex]) {
+ // First we check if the original source content was provided in the
+ // source map itself:
+ source = payload.sourcesContent[sourceContentIndex];
+ } else if (StringPrototypeStartsWith(originalSourcePath, 'file://')) {
+ // If no sourcesContent was found, attempt to load the original source
+ // from disk:
+ debug(`read source of ${originalSourcePath} from filesystem`);
+ const originalSourcePathNoScheme = fileURLToPath(originalSourcePath);
+ try {
+ source = readFileSync(originalSourcePathNoScheme, 'utf8');
+ } catch (err) {
+ debug(err);
+ }
+ }
+ return source;
+}
+
+/**
+ * Get the line of source in the source map.
+ * @param {import('internal/source_map/source_map').SourceMap} sourceMap
+ * @param {string} originalSourcePath path or url of the original source
+ * @param {number} originalLine line number in the original source
+ * @returns {string|undefined} source line if found
+ */
+function getSourceLine(
+ sourceMap,
+ originalSourcePath,
+ originalLine,
+) {
+ const source = getOriginalSource(
+ sourceMap.payload,
+ originalSourcePath,
+ );
+ if (typeof source !== 'string') {
+ return;
+ }
+ const lines = RegExpPrototypeSymbolSplit(/\r?\n/, source, originalLine + 1);
+ const line = lines[originalLine];
+ return line;
+}
+
 module.exports = {
  findSourceMap,
+ getSourceLine,
  getSourceMapsSupport,
  setSourceMapsSupport,
  maybeCacheSourceMap,

test/fixtures/source-map/output/source_map_assert_source_line.snapshot

@@ -0,0 +1,20 @@
+AssertionError [ERR_ASSERTION]: The expression evaluated to a falsy value:
+
+ assert(false)
+
+ at Object.<anonymous> (*/test/fixtures/source-map/output/source_map_assert_source_line.ts:11:3)
+ *
+ *
+ *
+ *
+ at TracingChannel.traceSync (node:diagnostics_channel:322:14)
+ *
+ *
+ *
+ generatedMessage: true,
+ code: 'ERR_ASSERTION',
+ actual: false,
+ expected: true,
+ operator: '==',
+ diff: 'simple'
+}

test/fixtures/source-map/output/source_map_assert_source_line.ts

@@ -0,0 +1,14 @@
+// Flags: --enable-source-maps --experimental-transform-types --no-warnings
+
+require('../../../common');
+const assert = require('node:assert');
+
+enum Bar {
+ makeSureTransformTypes,
+}
+
+try {
+ assert(false);
+} catch (e) {
+ console.log(e);
+}

test/fixtures/source-map/output/source_map_enclosing_function.snapshot

@@ -2,7 +2,6 @@
  throw err
  ^
 
-
 Error: an error!
  at functionD (*/test/fixtures/source-map/enclosing-call-site.js:16:17)
  at functionC (*/test/fixtures/source-map/enclosing-call-site.js:10:3)

test/fixtures/source-map/output/source_map_eval.snapshot

@@ -2,7 +2,6 @@
 alert "I knew it!"
 ^
 
-
 ReferenceError: alert is not defined
  at Object.eval (*/synthesized/workspace/tabs-source-url.coffee:26:2)
  at eval (*/synthesized/workspace/tabs-source-url.coffee:1:14)

test/fixtures/source-map/output/source_map_reference_error_tabs.snapshot

@@ -2,7 +2,6 @@
 alert "I knew it!"
 ^
 
-
 ReferenceError: alert is not defined
  at Object.<anonymous> (*/test/fixtures/source-map/tabs.coffee:26:2)
  at Object.<anonymous> (*/test/fixtures/source-map/tabs.coffee:1:14)

test/fixtures/source-map/output/source_map_throw_async_stack_trace.snapshot

@@ -2,7 +2,6 @@
  throw new Error('message')
  ^
 
-
 Error: message
  at Throw (*/test/fixtures/source-map/output/source_map_throw_async_stack_trace.mts:13:9)
  at async Promise.all (index 3)

test/fixtures/source-map/output/source_map_throw_construct.snapshot

@@ -2,7 +2,6 @@
  throw new Error('message');
  ^
 
-
 Error: message
  at new Foo (*/test/fixtures/source-map/output/source_map_throw_construct.mts:13:11)
  at <anonymous> (*/test/fixtures/source-map/output/source_map_throw_construct.mts:17:1)