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1'use strict';
2
3const {
4  ArrayPrototypeIndexOf,
5  ArrayPrototypeJoin,
6  ArrayPrototypeMap,
7  ErrorPrototypeToString,
8  StringPrototypeRepeat,
9  StringPrototypeSlice,
10  StringPrototypeSplit,
11  StringPrototypeStartsWith,
12  SafeStringIterator,
13} = primordials;
14
15let debug = require('internal/util/debuglog').debuglog('source_map', (fn) => {
16  debug = fn;
17});
18const { getStringWidth } = require('internal/util/inspect');
19const { readFileSync } = require('fs');
20const { findSourceMap } = require('internal/source_map/source_map_cache');
21const {
22  kNoOverride,
23  overrideStackTrace,
24  maybeOverridePrepareStackTrace
25} = require('internal/errors');
26const { fileURLToPath } = require('internal/url');
27
28// Create a prettified stacktrace, inserting context from source maps
29// if possible.
30const prepareStackTrace = (globalThis, error, trace) => {
31  // API for node internals to override error stack formatting
32  // without interfering with userland code.
33  // TODO(bcoe): add support for source-maps to repl.
34  if (overrideStackTrace.has(error)) {
35    const f = overrideStackTrace.get(error);
36    overrideStackTrace.delete(error);
37    return f(error, trace);
38  }
39
40  const globalOverride =
41    maybeOverridePrepareStackTrace(globalThis, error, trace);
42  if (globalOverride !== kNoOverride) return globalOverride;
43
44  const errorString = ErrorPrototypeToString(error);
45
46  if (trace.length === 0) {
47    return errorString;
48  }
49
50  let errorSource = '';
51  let lastSourceMap;
52  let lastFileName;
53  const preparedTrace = ArrayPrototypeJoin(ArrayPrototypeMap(trace, (t, i) => {
54    const str = i !== 0 ? '\n    at ' : '';
55    try {
56      // A stack trace will often have several call sites in a row within the
57      // same file, cache the source map and file content accordingly:
58      const fileName = t.getFileName();
59      const sm = fileName === lastFileName ?
60        lastSourceMap :
61        findSourceMap(fileName);
62      lastSourceMap = sm;
63      lastFileName = fileName;
64      if (sm) {
65        // Source Map V3 lines/columns start at 0/0 whereas stack traces
66        // start at 1/1:
67        const {
68          originalLine,
69          originalColumn,
70          originalSource,
71        } = sm.findEntry(t.getLineNumber() - 1, t.getColumnNumber() - 1);
72        if (originalSource && originalLine !== undefined &&
73            originalColumn !== undefined) {
74          const name = getOriginalSymbolName(sm, trace, i);
75          if (i === 0) {
76            errorSource = getErrorSource(
77              sm,
78              originalSource,
79              originalLine,
80              originalColumn
81            );
82          }
83          // Construct call site name based on: v8.dev/docs/stack-trace-api:
84          const fnName = t.getFunctionName() ?? t.getMethodName();
85          const originalName = `${t.getTypeName() !== 'global' ?
86            `${t.getTypeName()}.` : ''}${fnName ? fnName : '<anonymous>'}`;
87          // The original call site may have a different symbol name
88          // associated with it, use it:
89          const prefix = (name && name !== originalName) ?
90            `${name}` :
91            `${originalName ? originalName : ''}`;
92          const hasName = !!(name || originalName);
93          const originalSourceNoScheme =
94            StringPrototypeStartsWith(originalSource, 'file://') ?
95              fileURLToPath(originalSource) : originalSource;
96          // Replace the transpiled call site with the original:
97          return `${str}${prefix}${hasName ? ' (' : ''}` +
98            `${originalSourceNoScheme}:${originalLine + 1}:` +
99            `${originalColumn + 1}${hasName ? ')' : ''}`;
100        }
101      }
102    } catch (err) {
103      debug(err.stack);
104    }
105    return `${str}${t}`;
106  }), '');
107  return `${errorSource}${errorString}\n    at ${preparedTrace}`;
108};
109
110// Transpilers may have removed the original symbol name used in the stack
111// trace, if possible restore it from the names field of the source map:
112function getOriginalSymbolName(sourceMap, trace, curIndex) {
113  // First check for a symbol name associated with the enclosing function:
114  const enclosingEntry = sourceMap.findEntry(
115    trace[curIndex].getEnclosingLineNumber() - 1,
116    trace[curIndex].getEnclosingColumnNumber() - 1
117  );
118  if (enclosingEntry.name) return enclosingEntry.name;
119  // Fallback to using the symbol name attached to the next stack frame:
120  const currentFileName = trace[curIndex].getFileName();
121  const nextCallSite = trace[curIndex + 1];
122  if (nextCallSite && currentFileName === nextCallSite.getFileName()) {
123    const { name } = sourceMap.findEntry(
124      nextCallSite.getLineNumber() - 1,
125      nextCallSite.getColumnNumber() - 1
126    );
127    return name;
128  }
129}
130
131// Places a snippet of code from where the exception was originally thrown
132// above the stack trace. This logic is modeled after GetErrorSource in
133// node_errors.cc.
134function getErrorSource(
135  sourceMap,
136  originalSourcePath,
137  originalLine,
138  originalColumn
139) {
140  let exceptionLine = '';
141  const originalSourcePathNoScheme =
142    StringPrototypeStartsWith(originalSourcePath, 'file://') ?
143      fileURLToPath(originalSourcePath) : originalSourcePath;
144  const source = getOriginalSource(
145    sourceMap.payload,
146    originalSourcePathNoScheme
147  );
148  const lines = StringPrototypeSplit(source, /\r?\n/, originalLine + 1);
149  const line = lines[originalLine];
150  if (!line) return exceptionLine;
151
152  // Display ^ in appropriate position, regardless of whether tabs or
153  // spaces are used:
154  let prefix = '';
155  for (const character of new SafeStringIterator(
156    StringPrototypeSlice(line, 0, originalColumn + 1))) {
157    prefix += (character === '\t') ? '\t' :
158      StringPrototypeRepeat(' ', getStringWidth(character));
159  }
160  prefix = StringPrototypeSlice(prefix, 0, -1); // The last character is '^'.
161
162  exceptionLine =
163   `${originalSourcePathNoScheme}:${originalLine + 1}\n${line}\n${prefix}^\n\n`;
164  return exceptionLine;
165}
166
167function getOriginalSource(payload, originalSourcePath) {
168  let source;
169  const originalSourcePathNoScheme =
170    StringPrototypeStartsWith(originalSourcePath, 'file://') ?
171      fileURLToPath(originalSourcePath) : originalSourcePath;
172  const sourceContentIndex =
173    ArrayPrototypeIndexOf(payload.sources, originalSourcePath);
174  if (payload.sourcesContent?.[sourceContentIndex]) {
175    // First we check if the original source content was provided in the
176    // source map itself:
177    source = payload.sourcesContent[sourceContentIndex];
178  } else {
179    // If no sourcesContent was found, attempt to load the original source
180    // from disk:
181    try {
182      source = readFileSync(originalSourcePathNoScheme, 'utf8');
183    } catch (err) {
184      debug(err);
185      source = '';
186    }
187  }
188  return source;
189}
190
191module.exports = {
192  prepareStackTrace,
193};
194