replace some props on the object returned by getMode during compile time

build-system/runner/src/org/ampproject/AmpCommandLineRunner.java

@@ -35,6 +35,8 @@ public class AmpCommandLineRunner extends CommandLineRunner {
    * Identifies if the runner only needs to do type checking.
    */
   private boolean typecheck_only = false;
+
+  private boolean is_production_env = true;
 
   /**
    * List of string suffixes to eliminate from the AST.
@@ -52,7 +54,7 @@ protected AmpCommandLineRunner(String[] args) {
     }
     CompilerOptions options = super.createOptions();
     options.setCollapseProperties(true);
-    AmpPass ampPass = new AmpPass(getCompiler(), suffixTypes);
+    AmpPass ampPass = new AmpPass(getCompiler(), is_production_env, suffixTypes);
     options.addCustomPass(CustomPassExecutionTime.BEFORE_OPTIMIZATIONS, ampPass);
     options.setDevirtualizePrototypeMethods(true);
     options.setExtractPrototypeMemberDeclarations(true);
@@ -91,15 +93,20 @@ protected CompilerOptions createTypeCheckingOptions() {
   protected void setTypeCheckOnly(boolean value) {
     typecheck_only = value;
   }
+
+  protected void setProductionFlag(boolean value) {
+    is_production_env = value;
+  }
 
   public static void main(String[] args) {
     AmpCommandLineRunner runner = new AmpCommandLineRunner(args);
 
     // Scan for TYPECHECK_ONLY string which we pass in as a --define
     for (String arg : args) {
-      if (arg.contains("TYPECHECK_ONLY=true")) {
+      if (arg.contains("--define=TYPECHECK_ONLY=true")) {
         runner.setTypeCheckOnly(true);
-        break;
+      } else if (arg.contains("--define=FORTESTING=true")) {
+        runner.setProductionFlag(false);
       }
     }
 

build-system/runner/src/org/ampproject/AmpPass.java

@@ -17,10 +17,12 @@
 
 import java.util.Set;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.javascript.jscomp.AbstractCompiler;
 import com.google.javascript.jscomp.HotSwapCompilerPass;
 import com.google.javascript.jscomp.NodeTraversal;
 import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
+import com.google.javascript.rhino.IR;
 import com.google.javascript.rhino.Node;
 
 /**
@@ -41,10 +43,12 @@ class AmpPass extends AbstractPostOrderCallback implements HotSwapCompilerPass {
 
   final AbstractCompiler compiler;
   private final Set<String> stripTypeSuffixes;
+  final boolean isProd;
 
-  public AmpPass(AbstractCompiler compiler, Set<String> stripTypeSuffixes) {
+  public AmpPass(AbstractCompiler compiler, boolean isProd, Set<String> stripTypeSuffixes) {
     this.compiler = compiler;
     this.stripTypeSuffixes = stripTypeSuffixes;
+    this.isProd = isProd;
   }
 
   @Override public void process(Node externs, Node root) {
@@ -56,56 +60,93 @@ public AmpPass(AbstractCompiler compiler, Set<String> stripTypeSuffixes) {
   }
 
   @Override public void visit(NodeTraversal t, Node n, Node parent) {
-    if (isDevAssertCall(n)) {
+    // Remove `dev.assert` calls and preserve first argument if any.
+    if (isNameStripType(n, ImmutableSet.of( "dev.assert"))) {
       maybeEliminateCallExceptFirstParam(n, parent);
-    } else if (n.isExprResult()) {
-      maybeEliminateExpressionBySuffixName(n, parent);
+    // Remove any `stripTypes` passed in outright like `dev.warn`.
+    } else if (isNameStripType(n, stripTypeSuffixes)) {
+      removeExpression(n, parent);
+    // Remove any `getMode().localDev` and `getMode().test` calls and replace it with `false`.
+    } else if (isProd && isFunctionInvokeAndPropAccess(n, "$mode.getMode",
+        ImmutableSet.of("localDev", "test"))) {
+      replaceWithBooleanExpression(false, n, parent);
+    // Remove any `getMode().minified` calls and replace it with `true`.
+    } else if (isProd && isFunctionInvokeAndPropAccess(n, "$mode.getMode",
+        ImmutableSet.of("minified"))) {
+      replaceWithBooleanExpression(true, n, parent);
     }
   }
 
-  private boolean isDevAssertCall(Node n) {
-    if (n.isCall()) {
-      Node expression = n.getFirstChild();
-      if (expression == null) {
-        return false;
-      }
-
-      String name = expression.getQualifiedName();
-      if (name == null) {
-        return false;
-      }
+  /**
+   * Predicate for any <code>fnQualifiedName</code>.<code>props</code> call.
+   * example:
+   *   isFunctionInvokeAndPropAccess(n, "getMode", "test"); // matches `getMode().test`
+   */
+  private boolean isFunctionInvokeAndPropAccess(Node n, String fnQualifiedName, Set<String> props) {
+    // mode.getMode().localDev
+    // mode [property] ->
+    //   getMode [call] 
+    //   ${property} [string]
+    if (!n.isGetProp()) {
+      return false;
+    }
+    Node call = n.getFirstChild();
+    if (!call.isCall()) {
+      return false;
+    }
+    Node fullQualifiedFnName = call.getFirstChild();
+    if (fullQualifiedFnName == null) {
+      return false;
+    }
 
-      if (name.endsWith("dev.assert")) {
-        return true;
+    String qualifiedName = fullQualifiedFnName.getQualifiedName();
+    if (qualifiedName != null && qualifiedName.endsWith(fnQualifiedName)) {
+      Node maybeProp = n.getSecondChild();
+      if (maybeProp != null && maybeProp.isString()) {
+         String name = maybeProp.getString();
+         for (String prop : props) {
+           if (prop == name) {
+             return true;
+           }
+         }
       }
     }
+
     return false;
   }
 
+  private void replaceWithBooleanExpression(boolean bool, Node n, Node parent) {
+    Node booleanNode = bool ? IR.trueNode() : IR.falseNode();
+    booleanNode.useSourceInfoIfMissingFrom(n);
+    parent.replaceChild(n, booleanNode);
+    compiler.reportCodeChange();
+  }
+
   /**
    * Checks if expression is a GETPROP() (method invocation) and the property
    * name ends with one of the items in stripTypeSuffixes.
+   * This method does not do a deep check and will only do a shallow
+   * expression -> property -> call check.
    */
-  private void maybeEliminateExpressionBySuffixName(Node n, Node parent) {
-    // n = EXPRESSION_RESULT > CALL > GETPROP
-    Node call = n.getFirstChild();
-    if (call == null) {
-      return;
+  private boolean isNameStripType(Node n, Set<String> suffixes) {
+    if (!n.isCall()) {
+      return false;
     }
-    Node expression = call.getFirstChild();
-    if (expression == null) {
-      return;
+    Node getprop = n.getFirstChild();
+    if (getprop == null) {
+      return false;
     }
+    return qualifiedNameEndsWithStripType(getprop, suffixes);
+  }
 
-    if (qualifiedNameEndsWithStripType(expression)) {
-      if (parent.isExprResult()) {
-        Node grandparent = parent.getParent();
-        grandparent.removeChild(parent);
-      } else {
-        parent.removeChild(n);
-      }
-      compiler.reportCodeChange();
+  private void removeExpression(Node n, Node parent) {
+    if (parent.isExprResult()) {
+      Node grandparent = parent.getParent();
+      grandparent.removeChild(parent);
+    } else {
+      parent.removeChild(n);
     }
+    compiler.reportCodeChange();
   }
 
   private void maybeEliminateCallExceptFirstParam(Node n, Node p) {
@@ -130,17 +171,17 @@ private void maybeEliminateCallExceptFirstParam(Node n, Node p) {
    * Checks the nodes qualified name if it ends with one of the items in
    * stripTypeSuffixes
    */
-  boolean qualifiedNameEndsWithStripType(Node n) {
+  boolean qualifiedNameEndsWithStripType(Node n, Set<String> suffixes) {
     String name = n.getQualifiedName();
-    return qualifiedNameEndsWithStripType(name);
+    return qualifiedNameEndsWithStripType(name, suffixes);
   }
 
   /**
    * Checks if the string ends with one of the items in stripTypeSuffixes
    */
-  boolean qualifiedNameEndsWithStripType(String name) {
+  boolean qualifiedNameEndsWithStripType(String name, Set<String> suffixes) {
     if (name != null) {
-      for (String suffix : stripTypeSuffixes) {
+      for (String suffix : suffixes) {
         if (name.endsWith(suffix)) {
           return true;
         }

build-system/runner/test/org/ampproject/AmpPassTest.java

@@ -17,7 +17,7 @@ public class AmpPassTest extends Es6CompilerTestCase {
       "dev.fine");
 
   @Override protected CompilerPass getProcessor(Compiler compiler) {
-    return new AmpPass(compiler, suffixTypes);
+    return new AmpPass(compiler, /* isProd */ true, suffixTypes);
   }
 
   @Override protected int getNumRepetitions() {
@@ -129,4 +129,101 @@ public void testShouldPreserveNoneCalls() throws Exception {
              "  console.log('this is preserved', someValue);",
             "})()"));
   }
+
+  public void testGetModeLocalDevPropertyReplacement() throws Exception {
+    test(
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { localDev: true } }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode().localDev) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"),
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { localDev: true }; }",
+             "var $mode = { getMode: getMode };",
+             "  if (false) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"));
+  }
+
+  public void testGetModeTestPropertyReplacement() throws Exception {
+    test(
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { test: true } }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode().test) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"),
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { test: true }; }",
+             "var $mode = { getMode: getMode };",
+             "  if (false) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"));
+  }
+
+  public void testGetModeMinifiedPropertyReplacement() throws Exception {
+    test(
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { minified: false } }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode().minified) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"),
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { minified: false }; }",
+             "var $mode = { getMode: getMode };",
+             "  if (true) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"));
+  }
+
+  public void testGetModePreserve() throws Exception {
+    test(
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { minified: false } }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode()) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"),
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { minified: false }; }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode()) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"));
+    test(
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { otherProp: true } }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode().otherProp) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"),
+        LINE_JOINER.join(
+             "(function() {",
+             "function getMode() { return { otherProp: true }; }",
+             "var $mode = { getMode: getMode };",
+             "  if ($mode.getMode().otherProp) {",
+             "    console.log('hello world');",
+             "  }",
+            "})()"));
+  }
 }