Add public API generation with cr.makePublic() and handle it in compiler pass

third_party/closure_compiler/runner/src/com/google/javascript/jscomp/ChromePass.java

Index: third_party/closure_compiler/runner/src/com/google/javascript/jscomp/ChromePass.java
diff --git a/third_party/closure_compiler/runner/src/com/google/javascript/jscomp/ChromePass.java b/third_party/closure_compiler/runner/src/com/google/javascript/jscomp/ChromePass.java
index c7f3c12daccb071f705a6a6a9c896653b3045a37..fd9821451507d5103cbff4c9908e4d8b722f3808 100644
--- a/third_party/closure_compiler/runner/src/com/google/javascript/jscomp/ChromePass.java
+++ b/third_party/closure_compiler/runner/src/com/google/javascript/jscomp/ChromePass.java
@@ -37,6 +37,7 @@ public class ChromePass extends AbstractPostOrderCallback implements CompilerPas
     private static final String CR_EXPORT_PATH = "cr.exportPath";
     private static final String OBJECT_DEFINE_PROPERTY = "Object.defineProperty";
     private static final String CR_DEFINE_PROPERTY = "cr.defineProperty";
+    private static final String CR_MAKE_PUBLIC = "cr.makePublic";
 
     private static final String CR_DEFINE_COMMON_EXPLANATION = "It should be called like this:"
             + " cr.define('name.space', function() '{ ... return {Export: Internal}; }');";
@@ -67,6 +68,14 @@ public class ChromePass extends AbstractPostOrderCallback implements CompilerPas
                     "Invalid cr.PropertyKind passed to cr.defineProperty(): expected ATTR,"
                     + " BOOL_ATTR or JS, found \"{0}\".");
 
+    static final DiagnosticType CR_MAKE_PUBLIC_HAS_NO_JSDOC =
+            DiagnosticType.error("JSC_CR_MAKE_PUBLIC_HAS_NO_JSDOC",
+                    "Private method exported by cr.makePublic() has no JSDoc.");
+
+    static final DiagnosticType CR_MAKE_PUBLIC_MISSED_DECLARATION =
+            DiagnosticType.error("CR_MAKE_PUBLIC_MISSED_DECLARATION",
+                    "Method \"{1}_\" exported by cr.makePublic() on \"{0}\" has no declaration.");
+
     public ChromePass(AbstractCompiler compiler) {
         this.compiler = compiler;
         // The global variable "cr" is declared in ui/webui/resources/js/cr.js.
@@ -92,6 +101,10 @@ public class ChromePass extends AbstractPostOrderCallback implements CompilerPas
                     callee.matchesQualifiedName(CR_DEFINE_PROPERTY)) {
                 visitPropertyDefinition(node, parent);
                 compiler.reportCodeChange();
+            } else if (callee.matchesQualifiedName(CR_MAKE_PUBLIC)) {
+                if (visitMakePublic(node, parent)) {
+                    compiler.reportCodeChange();
+                }
             }
         }
     }
@@ -140,6 +153,62 @@ public class ChromePass extends AbstractPostOrderCallback implements CompilerPas
         target.setJSDocInfo(builder.build(target));
     }
 
+    private boolean visitMakePublic(Node call, Node exprResult) {
+        boolean changesMade = false;
+        Node scope = exprResult.getParent();
+        String className = call.getChildAtIndex(1).getQualifiedName();
+        String prototype = className  + ".prototype";
+        Node publicAPI = call.getChildAtIndex(2);
+
+        assert publicAPI != null && publicAPI.isArrayLit();
+
+        Set<String> publicAPIStrings = new HashSet<>();
+        for (Node methodName: publicAPI.children()) {
+            assert methodName.isString();
+            publicAPIStrings.add(methodName.getString());
+        }
+
+        for (Node child: scope.children()) {
+            if (isAssignmentToPrototype(child, prototype)) {
+                Node objectLit = child.getFirstChild().getChildAtIndex(1);
+                for (Node stringKey : objectLit.children()) {
+                    String field = stringKey.getString();
+                    if (field.endsWith("_")) {
+                        String publicName = field.substring(0, field.length() - 1);
+                        if (publicAPIStrings.contains(publicName)) {
+                            Node methodDeclaration = NodeUtil.newQualifiedNameNode(
+                                    compiler.getCodingConvention(), className + "." + publicName);
+                            if (stringKey.getJSDocInfo() != null) {
+                                methodDeclaration.setJSDocInfo(stringKey.getJSDocInfo());
+                                scope.addChildBefore(
+                                        IR.exprResult(methodDeclaration).srcrefTree(exprResult),
+                                        exprResult);
+                                changesMade = true;
+                            } else {
+                                compiler.report(JSError.make(stringKey,
+                                        CR_MAKE_PUBLIC_HAS_NO_JSDOC));
+                            }
+                            publicAPIStrings.remove(publicName);
+                        }
+                    }
+                }
+            }
+        }
+
+        for (String missedDeclaration : publicAPIStrings) {
+            compiler.report(JSError.make(exprResult, CR_MAKE_PUBLIC_MISSED_DECLARATION, className,
+                    missedDeclaration));
+        }
+
+        return changesMade;
+    }
+
+    private boolean isAssignmentToPrototype(Node node, String prototype) {
+        Node assignNode;
+        return node.isExprResult() && (assignNode = node.getFirstChild()).isAssign() &&
+                assignNode.getFirstChild().getQualifiedName().equals(prototype);
+    }
+
     private void visitExportPath(Node crExportPathNode, Node parent) {
         if (crExportPathNode.getChildCount() != 2) {
             compiler.report(JSError.make(crExportPathNode,
@@ -342,5 +411,4 @@ public class ChromePass extends AbstractPostOrderCallback implements CompilerPas
                     this.namespaceName + "." + externalName).srcrefTree(internalName);
         }
     }
-
 }