Stop serializing inline source maps (base64-encoded "data urls") in TypedAST

There are 2 kinds of source maps.
#### 1) Input source map
A source map for a file passed as an input to JSCompiler. This can be passed in one of two ways:
1) the `--source_map_input_files` flag
2) a special comment embedded into the input JS file: `//# sourceMappingURL=<url>`
Where the "<url>" points to the source map content.

#### 2) Inline source map
An input source map passed by embedding a sourceMappingURL as a base64-encoded "data url".

We want TypedAST to support input source maps and not inline source maps. This change stops serializing inline source map URLs in TypedAST.

PiperOrigin-RevId: 500744410

Author: rahul-kamat

src/com/google/javascript/jscomp/AbstractCompiler.java

@@ -519,7 +519,7 @@ public boolean hasColorAndSimplifiedJSDoc() {
    */
   public abstract void addInputSourceMap(String name, SourceMapInput sourceMap);
 
-  public abstract SourceMapInput getInputSourceMap(String sourceFileName);
+  public abstract String getInputSourceMappingURL(String sourceFileName);
 
   abstract void addComments(String filename, List<Comment> comments);
 

src/com/google/javascript/jscomp/Compiler.java

@@ -3269,9 +3269,23 @@ public void addInputSourceMap(String sourceFileName, SourceMapInput inputSourceM
     }
   }
 
+  /**
+   * Returns the <url> from a `//# sourceMappingURL=<url>` comment. This sourceMappingURL is a JS
+   * file's input source map, embedded into the input JS file with a `//# sourceMappingURL=<url>`
+   * comment.
+   *
+   * <p>We do not want TypedAST to support inline source maps (which are input source maps passed by
+   * embedding a `//# sourceMappingURL=<url>` where <url> is a base64-encoded "data url"). If the
+   * sourceMappingURL ends with a ".inline.map", return null.
+   */
   @Override
-  public @Nullable SourceMapInput getInputSourceMap(String sourceFileName) {
-    return inputSourceMaps.getOrDefault(sourceFileName, null);
+  public @Nullable String getInputSourceMappingURL(String sourceFileName) {
+    SourceMapInput sourceMapInput = inputSourceMaps.getOrDefault(sourceFileName, null);
+    String sourceMappingURL = sourceMapInput != null ? sourceMapInput.getOriginalPath() : null;
+    if (sourceMappingURL != null && !sourceMappingURL.endsWith(".inline.map")) {
+      return sourceMappingURL;
+    }
+    return null;
   }
 
   /**

src/com/google/javascript/jscomp/serialization/TypedAstSerializer.java

@@ -28,7 +28,6 @@
 import com.google.javascript.jscomp.NodeTraversal;
 import com.google.javascript.jscomp.NodeUtil;
 import com.google.javascript.jscomp.SourceFile;
-import com.google.javascript.jscomp.SourceMapInput;
 import com.google.javascript.jscomp.colors.Color;
 import com.google.javascript.jscomp.colors.ColorId;
 import com.google.javascript.jscomp.colors.ColorRegistry;
@@ -119,8 +118,7 @@ private LazyAst serializeScriptNode(Node script) {
     AstNode scriptProto = visit(script);
     this.subtreeSourceFiles.clear();
 
-    SourceMapInput sourceMapInput = compiler.getInputSourceMap(script.getSourceFileName());
-    String sourceMappingURL = sourceMapInput != null ? sourceMapInput.getOriginalPath() : null;
+    String sourceMappingURL = compiler.getInputSourceMappingURL(script.getSourceFileName());
 
     LazyAst.Builder lazyAstBuilder =
         LazyAst.newBuilder().setScript(scriptProto.toByteString()).setSourceFile(sourceFile);

test/com/google/javascript/jscomp/serialization/SerializeAndDeserializeAstTest.java

@@ -419,8 +419,7 @@ public void testSourceMaps() {
     String code = sourceMapTestCode + "\n" + sourceMappingURLComment;
 
     Result result = testAndReturnResult(srcs(code), expected(code));
-    assertThat(result.compiler.getInputSourceMap("testcode").getOriginalPath())
-        .isEqualTo(sourceMapPath);
+    assertThat(result.compiler.getInputSourceMappingURL("testcode")).isEqualTo(sourceMapPath);
   }
 
   @Test
@@ -440,7 +439,7 @@ public void testSourceMapsWithoutResolvingSourceMapAnnotations() {
 
     Result result = testAndReturnResult(srcs(code), expected(code));
     // Input source map not registered because `resolveSourceMapAnnotations = false`
-    assertThat(result.compiler.getInputSourceMap("testcode")).isNull();
+    assertThat(result.compiler.getInputSourceMappingURL("testcode")).isNull();
   }
 
   @Test
@@ -461,8 +460,7 @@ public void testSourceMapsWithoutParsingInlineSourceMaps() {
     Result result = testAndReturnResult(srcs(code), expected(code));
     // Input source map is registered when `parseInlineSourceMaps = false`, but we won't try to
     // parse it as a Base64 encoded source map.
-    assertThat(result.compiler.getInputSourceMap("testcode").getOriginalPath())
-        .isEqualTo(sourceMapPath);
+    assertThat(result.compiler.getInputSourceMappingURL("testcode")).isEqualTo(sourceMapPath);
   }
 
   @Test

test/com/google/javascript/jscomp/serialization/SerializeTypedAstPassTest.java

@@ -445,6 +445,32 @@ public void serializesSourceMappingURL() throws InvalidProtocolBufferException {
     assertThat(sourceMappingURL).isEqualTo("relativedir/foo.js.map");
   }
 
+  @Test
+  public void doesNotSerializeInlineSourceMappingURL() throws InvalidProtocolBufferException {
+    // We do not want TypedAST to support inline source maps (which are input source maps passed
+    // by embedding a `//# sourceMappingURL=<url>` where <url> is a base64-encoded "data url").
+    String sourceMapTestCode =
+        lines(
+            "var X = (function () {",
+            "    function X(input) {",
+            "        this.y = input;",
+            "    }",
+            "    return X;",
+            "}());");
+
+    String base64EncodedSourceMappingURL =
+        "data:application/json;base64,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";
+
+    String code = sourceMapTestCode + "\n//# sourceMappingURL=" + base64EncodedSourceMappingURL;
+
+    SerializationResult result = compile(code);
+
+    LazyAst lazyAst = result.ast.getCodeAstList().get(0);
+    String sourceMappingURL = lazyAst.getSourceMappingUrl();
+
+    assertThat(sourceMappingURL).isEmpty(); // Do not serizile this base-64 sourceMappingURL.
+  }
+
   private AstNode compileToAstNode(String source) {
     return compile(source).sourceNodes.get(0);
   }