Allow to embed source files into JS source maps

js/js.parser/src/org/jetbrains/kotlin/js/parser/sourcemaps/SourceMap.kt

@@ -16,7 +16,9 @@
 
 package org.jetbrains.kotlin.js.parser.sourcemaps
 
-class SourceMap {
+import java.io.Reader
+
+class SourceMap(val sourceContentResolver: (String) -> Reader?) {
     val groups = mutableListOf<SourceMapGroup>()
 }
 

js/js.parser/src/org/jetbrains/kotlin/js/parser/sourcemaps/SourceMapLocationRemapper.kt

@@ -16,10 +16,7 @@
 
 package org.jetbrains.kotlin.js.parser.sourcemaps
 
-import org.jetbrains.kotlin.js.backend.ast.JsLocation
-import org.jetbrains.kotlin.js.backend.ast.JsNode
-import org.jetbrains.kotlin.js.backend.ast.RecursiveJsVisitor
-import org.jetbrains.kotlin.js.backend.ast.SourceInfoAwareJsNode
+import org.jetbrains.kotlin.js.backend.ast.*
 
 class SourceMapLocationRemapper(val sourceMaps: Map<String, SourceMap>) {
     fun remap(node: JsNode) {
@@ -62,7 +59,8 @@ class SourceMapLocationRemapper(val sourceMaps: Map<String, SourceMap>) {
             }
 
             val segment = group.segments[lastSegmentIndex]
-            node.source = JsLocation(segment.sourceFileName, segment.sourceLineNumber, segment.sourceColumnNumber)
+            val location = JsLocation(segment.sourceFileName, segment.sourceLineNumber, segment.sourceColumnNumber)
+            node.source = JsLocationWithEmbeddedSource(location, sourceMap) { sourceMap.sourceContentResolver(segment.sourceFileName) }
 
             return true
         }

js/js.parser/src/org/jetbrains/kotlin/js/parser/sourcemaps/SourceMapParser.kt

@@ -38,6 +38,7 @@ import org.json.JSONObject
 import org.json.JSONTokener
 import java.io.IOException
 import java.io.Reader
+import java.io.StringReader
 
 object SourceMapParser {
     @Throws(IOException::class)
@@ -72,6 +73,20 @@ object SourceMapParser {
             emptyList()
         }
 
+        val sourcesContent: List<String?> = if (jsonObject.has("sourcesContent")) {
+            val sourcesContentProperty = jsonObject.get("sourcesContent") as? JSONArray ?:
+                                         return SourceMapError("'sourcesContent' property is not of array type")
+            if (sourcesContentProperty.any { it != JSONObject.NULL && it !is String? }) {
+                return SourceMapError("'sources' array must contain strings")
+            }
+            sourcesContentProperty.map { if (it == JSONObject.NULL) null else it as String? }
+        }
+        else {
+            emptyList()
+        }
+
+        val sourcePathToContent = sources.zip(sourcesContent).associate { it }
+
         if (!jsonObject.has("mappings")) return SourceMapError("'mappings' property not found")
         val mappings = jsonObject.get("mappings") as? String ?: return SourceMapError("'mappings' property is not of string type")
 
@@ -80,7 +95,7 @@ object SourceMapParser {
         var sourceColumn = 0
         var sourceIndex = 0
         val stream = MappingStream(mappings)
-        val sourceMap = SourceMap()
+        val sourceMap = SourceMap { sourcePathToContent[it]?.let { StringReader(it) } }
         var currentGroup = SourceMapGroup().also { sourceMap.groups += it }
 
         while (!stream.isEof) {