yeet

node_modules/metro-source-map/src/composeSourceMaps.js.flow

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+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+'use strict';
+
+// eslint-disable-next-line lint/sort-requires
+const Consumer = require('./Consumer');
+const {SourceMapGenerator} = require('source-map');
+
+import type {IConsumer, MixedSourceMap} from './source-map';
+import type {Number0, Number1} from 'ob1';
+
+// Originally based on https://github.com/jakobwesthoff/source-map-merger
+function composeSourceMaps(
+  maps: $ReadOnlyArray<MixedSourceMap>,
+): MixedSourceMap {
+  // NOTE: require() here to break dependency cycle
+  const SourceMetadataMapConsumer = require('metro-symbolicate/src/SourceMetadataMapConsumer');
+  if (maps.length < 1) {
+    throw new Error('composeSourceMaps: Expected at least one map');
+  }
+  const firstMap = maps[0];
+
+  const consumers = maps
+    .map(function(map) {
+      return new Consumer(map);
+    })
+    .reverse();
+
+  const generator = new SourceMapGenerator({
+    file: consumers[0].file,
+  });
+
+  consumers[0].eachMapping(mapping => {
+    const original = findOriginalPosition(
+      consumers,
+      mapping.generatedLine,
+      mapping.generatedColumn,
+    );
+    generator.addMapping({
+      generated: {
+        line: mapping.generatedLine,
+        column: mapping.generatedColumn,
+      },
+      original:
+        original.line != null
+          ? {
+              line: original.line,
+              column: original.column,
+            }
+          : null,
+      source: original.source,
+      name: original.name,
+    });
+  });
+
+  const composedMap = generator.toJSON();
+
+  const metadataConsumer = new SourceMetadataMapConsumer(firstMap);
+  composedMap.x_facebook_sources = metadataConsumer.toArray(
+    composedMap.sources,
+  );
+  const function_offsets = maps[maps.length - 1].x_hermes_function_offsets;
+  if (function_offsets) {
+    composedMap.x_hermes_function_offsets = function_offsets;
+  }
+  return composedMap;
+}
+
+function findOriginalPosition(
+  consumers: $ReadOnlyArray<IConsumer>,
+  generatedLine: Number1,
+  generatedColumn: Number0,
+): {
+  line: ?number,
+  column: ?number,
+  source: ?string,
+  name: ?string,
+  ...
+} {
+  let currentLine = generatedLine;
+  let currentColumn = generatedColumn;
+  let original = {
+    line: null,
+    column: null,
+    source: null,
+    name: null,
+  };
+
+  for (const consumer of consumers) {
+    if (currentLine == null || currentColumn == null) {
+      return {line: null, column: null, source: null, name: null};
+    }
+    original = consumer.originalPositionFor({
+      line: currentLine,
+      column: currentColumn,
+    });
+
+    currentLine = original.line;
+    currentColumn = original.column;
+
+    if (currentLine == null) {
+      return {
+        line: null,
+        column: null,
+        source: null,
+        name: null,
+      };
+    }
+  }
+  return original;
+}
+
+module.exports = composeSourceMaps;