/
merge-map.js
317 lines (277 loc) 路 8.31 KB
/
merge-map.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
// @flow
import typeof { SourceMap } from "convert-source-map";
import sourceMap from "source-map";
export default function mergeSourceMap(
inputMap: SourceMap,
map: SourceMap,
): SourceMap {
const input = buildMappingData(inputMap);
const output = buildMappingData(map);
const mergedGenerator = new sourceMap.SourceMapGenerator();
for (const { source } of input.sources) {
if (typeof source.content === "string") {
mergedGenerator.setSourceContent(source.path, source.content);
}
}
if (output.sources.length === 1) {
const defaultSource = output.sources[0];
const insertedMappings = new Map();
// Process each generated range in the input map, e.g. each range over the
// code that Babel was originally given.
eachInputGeneratedRange(input, (generated, original, source) => {
// Then pick out each range over Babel's _output_ that corresponds with
// the given range on the code given to Babel.
eachOverlappingGeneratedOutputRange(defaultSource, generated, item => {
// It's possible that multiple input ranges will overlap the same
// generated range. Since sourcemap don't traditionally represent
// generated locations with multiple original locations, we explicitly
// skip generated locations once we've seen them the first time.
const key = makeMappingKey(item);
if (insertedMappings.has(key)) return;
insertedMappings.set(key, item);
mergedGenerator.addMapping({
source: source.path,
original: {
line: original.line,
column: original.columnStart,
},
generated: {
line: item.line,
column: item.columnStart,
},
name: original.name,
});
});
});
// Since mappings are manipulated using single locations, but are interpreted
// as ranges, the insertions above may not actually have their ending
// locations mapped yet. Here be go through each one and ensure that it has
// a well-defined ending location, if one wasn't already created by the start
// of a different range.
for (const item of insertedMappings.values()) {
if (item.columnEnd === Infinity) {
continue;
}
const clearItem = {
line: item.line,
columnStart: item.columnEnd,
};
const key = makeMappingKey(clearItem);
if (insertedMappings.has(key)) {
continue;
}
// Insert mappings with no original position to terminate any mappings
// that were found above, so that they don't expand beyond their correct
// range.
mergedGenerator.addMapping({
generated: {
line: clearItem.line,
column: clearItem.columnStart,
},
});
}
}
const result = mergedGenerator.toJSON();
// addMapping expects a relative path, and setSourceContent expects an
// absolute path. To avoid this whole confusion, we leave the root out
// entirely, and add it at the end here.
if (typeof input.sourceRoot === "string") {
result.sourceRoot = input.sourceRoot;
}
return result;
}
function makeMappingKey(item: { line: number, columnStart: number }) {
return `${item.line}/${item.columnStart}`;
}
function eachOverlappingGeneratedOutputRange(
outputFile: ResolvedFileMappings,
inputGeneratedRange: ResolvedGeneratedRange,
callback: ResolvedGeneratedRange => mixed,
) {
// Find the Babel-generated mappings that overlap with this range in the
// input sourcemap. Generated locations within the input sourcemap
// correspond with the original locations in the map Babel generates.
const overlappingOriginal = filterApplicableOriginalRanges(
outputFile,
inputGeneratedRange,
);
for (const { generated } of overlappingOriginal) {
for (const item of generated) {
callback(item);
}
}
}
function filterApplicableOriginalRanges(
{ mappings }: ResolvedFileMappings,
{ line, columnStart, columnEnd }: ResolvedGeneratedRange,
): OriginalMappings {
// The mapping array is sorted by original location, so we can
// binary-search it for the overlapping ranges.
return filterSortedArray(mappings, ({ original: outOriginal }) => {
if (line > outOriginal.line) return -1;
if (line < outOriginal.line) return 1;
if (columnStart >= outOriginal.columnEnd) return -1;
if (columnEnd <= outOriginal.columnStart) return 1;
return 0;
});
}
function eachInputGeneratedRange(
map: ResolvedMappings,
callback: (
ResolvedGeneratedRange,
ResolvedOriginalRange,
ResolvedSource,
) => mixed,
) {
for (const { source, mappings } of map.sources) {
for (const { original, generated } of mappings) {
for (const item of generated) {
callback(item, original, source);
}
}
}
}
type ResolvedMappings = {|
file: ?string,
sourceRoot: ?string,
sources: Array<ResolvedFileMappings>,
|};
type ResolvedFileMappings = {|
source: ResolvedSource,
mappings: OriginalMappings,
|};
type OriginalMappings = Array<{|
original: ResolvedOriginalRange,
generated: Array<ResolvedGeneratedRange>,
|}>;
type ResolvedSource = {|
path: string,
content: string | null,
|};
type ResolvedOriginalRange = {|
line: number,
columnStart: number,
columnEnd: number,
name: string | null,
|};
type ResolvedGeneratedRange = {|
line: number,
columnStart: number,
columnEnd: number,
|};
function buildMappingData(map: SourceMap): ResolvedMappings {
const consumer = new sourceMap.SourceMapConsumer({
...map,
// This is a bit hack. .addMapping expects source values to be relative,
// but eachMapping returns mappings with absolute paths. To avoid that
// incompatibility, we leave the sourceRoot out here and add it to the
// final map at the end instead.
sourceRoot: null,
});
const sources = new Map();
const mappings = new Map();
let last = null;
consumer.computeColumnSpans();
consumer.eachMapping(
m => {
if (m.originalLine === null) return;
let source = sources.get(m.source);
if (!source) {
source = {
path: m.source,
content: consumer.sourceContentFor(m.source, true),
};
sources.set(m.source, source);
}
let sourceData = mappings.get(source);
if (!sourceData) {
sourceData = {
source,
mappings: [],
};
mappings.set(source, sourceData);
}
const obj = {
line: m.originalLine,
columnStart: m.originalColumn,
columnEnd: Infinity,
name: m.name,
};
if (
last &&
last.source === source &&
last.mapping.line === m.originalLine
) {
last.mapping.columnEnd = m.originalColumn;
}
last = {
source,
mapping: obj,
};
sourceData.mappings.push({
original: obj,
generated: consumer
.allGeneratedPositionsFor({
source: m.source,
line: m.originalLine,
column: m.originalColumn,
})
.map(item => ({
line: item.line,
columnStart: item.column,
// source-map's lastColumn is inclusive, not exclusive, so we need
// to add 1 to it.
columnEnd: item.lastColumn + 1,
})),
});
},
null,
sourceMap.SourceMapConsumer.ORIGINAL_ORDER,
);
return {
file: map.file,
sourceRoot: map.sourceRoot,
sources: Array.from(mappings.values()),
};
}
function findInsertionLocation<T>(
array: Array<T>,
callback: T => number,
): number {
let left = 0;
let right = array.length;
while (left < right) {
const mid = Math.floor((left + right) / 2);
const item = array[mid];
const result = callback(item);
if (result === 0) {
left = mid;
break;
}
if (result >= 0) {
right = mid;
} else {
left = mid + 1;
}
}
// Ensure the value is the start of any set of matches.
let i = left;
if (i < array.length) {
while (i >= 0 && callback(array[i]) >= 0) {
i--;
}
return i + 1;
}
return i;
}
function filterSortedArray<T>(
array: Array<T>,
callback: T => number,
): Array<T> {
const start = findInsertionLocation(array, callback);
const results = [];
for (let i = start; i < array.length && callback(array[i]) === 0; i++) {
results.push(array[i]);
}
return results;
}