refactor!: replace source-map with @jridgewell/trace-mapping (#685)

packages/istanbul-lib-source-maps/lib/get-mapping.js

@@ -6,9 +6,11 @@
 
 const pathutils = require('./pathutils');
 const {
+    originalPositionFor,
+    generatedPositionFor,
     GREATEST_LOWER_BOUND,
     LEAST_UPPER_BOUND
-} = require('source-map').SourceMapConsumer;
+} = require('@jridgewell/trace-mapping');
 
 /**
  * AST ranges are inclusive for start positions and exclusive for end positions.
@@ -48,31 +50,31 @@ function originalEndPositionFor(sourceMap, generatedEnd) {
     // for mappings in the original-order sorted list, this will find the
     // mapping that corresponds to the one immediately after the
     // beforeEndMapping mapping.
-    const afterEndMappings = sourceMap.allGeneratedPositionsFor({
+    const afterEndMapping = generatedPositionFor(sourceMap, {
         source: beforeEndMapping.source,
         line: beforeEndMapping.line,
         column: beforeEndMapping.column + 1,
         bias: LEAST_UPPER_BOUND
     });
-
-    for (let i = 0; i < afterEndMappings.length; i++) {
-        const afterEndMapping = afterEndMappings[i];
-        if (afterEndMapping.line === null) continue;
-
-        const original = sourceMap.originalPositionFor(afterEndMapping);
-        // If the lines match, it means that something comes after our mapping,
-        // so it must end where this one begins.
-        if (original.line === beforeEndMapping.line) return original;
+    if (
+        // If this is null, it means that we've hit the end of the file,
+        // so we can use Infinity as the end column.
+        afterEndMapping.line === null ||
+        // If these don't match, it means that the call to
+        // 'generatedPositionFor' didn't find any other original mappings on
+        // the line we gave, so consider the binding to extend to infinity.
+        originalPositionFor(sourceMap, afterEndMapping).line !==
+            beforeEndMapping.line
+    ) {
+        return {
+            source: beforeEndMapping.source,
+            line: beforeEndMapping.line,
+            column: Infinity
+        };
     }
 
-    // If a generated mapping wasn't found (or all that were found were not on
-    // the same line), then there's nothing after this range and we can
-    // consider it to extend to infinity.
-    return {
-        source: beforeEndMapping.source,
-        line: beforeEndMapping.line,
-        column: Infinity
-    };
+    // Convert the end mapping into the real original position.
+    return originalPositionFor(sourceMap, afterEndMapping);
 }
 
 /**
@@ -81,13 +83,13 @@ function originalEndPositionFor(sourceMap, generatedEnd) {
  * and next returning the closest element to the right (LEAST_UPPER_BOUND).
  */
 function originalPositionTryBoth(sourceMap, line, column) {
-    const mapping = sourceMap.originalPositionFor({
+    const mapping = originalPositionFor(sourceMap, {
         line,
         column,
         bias: GREATEST_LOWER_BOUND
     });
     if (mapping.source === null) {
-        return sourceMap.originalPositionFor({
+        return originalPositionFor(sourceMap, {
             line,
             column,
             bias: LEAST_UPPER_BOUND
@@ -156,7 +158,7 @@ function getMapping(sourceMap, generatedLocation, origFile) {
     }
 
     if (start.line === end.line && start.column === end.column) {
-        end = sourceMap.originalPositionFor({
+        end = originalPositionFor(sourceMap, {
             line: generatedLocation.end.line,
             column: generatedLocation.end.column,
             bias: LEAST_UPPER_BOUND

packages/istanbul-lib-source-maps/lib/map-store.js

@@ -7,7 +7,7 @@
 const path = require('path');
 const fs = require('fs');
 const debug = require('debug')('istanbuljs');
-const { SourceMapConsumer } = require('source-map');
+const { TraceMap, sourceContentFor } = require('@jridgewell/trace-mapping');
 const pathutils = require('./pathutils');
 const { SourceMapTransformer } = require('./transformer');
 
@@ -190,9 +190,9 @@ class MapStore {
                         return null;
                     }
 
-                    const smc = new SourceMapConsumer(obj);
+                    const smc = new TraceMap(obj);
                     smc.sources.forEach(s => {
-                        const content = smc.sourceContentFor(s);
+                        const content = sourceContentFor(smc, s);
                         if (content) {
                             const sourceFilePath = pathutils.relativeTo(
                                 s,

packages/istanbul-lib-source-maps/package.json

@@ -12,9 +12,9 @@
     "test": "nyc mocha"
   },
   "dependencies": {
+    "@jridgewell/trace-mapping": "^0.3.23",
     "debug": "^4.1.1",
-    "istanbul-lib-coverage": "^3.0.0",
-    "source-map": "^0.6.1"
+    "istanbul-lib-coverage": "^3.0.0"
   },
   "devDependencies": {
     "chai": "^4.2.0",

packages/istanbul-lib-source-maps/test/transformer.test.js

@@ -3,7 +3,7 @@
 const path = require('path');
 const assert = require('chai').assert;
 const createMap = require('istanbul-lib-coverage').createCoverageMap;
-const { SourceMapConsumer } = require('source-map');
+const { TraceMap } = require('@jridgewell/trace-mapping');
 const { SourceMapTransformer } = require('../lib/transformer');
 
 const coverageData = {
@@ -84,7 +84,7 @@ describe('transformer', () => {
         coverageMap.addFileCoverage(testDataSlash.coverageData);
 
         const transformer = new SourceMapTransformer(
-            () => new SourceMapConsumer(testDataSlash.sourceMap)
+            () => new TraceMap(testDataSlash.sourceMap)
         );
         const mapped = await transformer.transform(coverageMap);
 
@@ -111,7 +111,7 @@ describe('transformer', () => {
 
         const transformer = new SourceMapTransformer(file =>
             file === testDataSlash.coverageData.path
-                ? new SourceMapConsumer(testDataSlash.sourceMap)
+                ? new TraceMap(testDataSlash.sourceMap)
                 : undefined
         );
         const mapped = await transformer.transform(coverageMap);