com.google.javascript.jscomp.lint.CheckRequiresAndProvidesSorted Maven / Gradle / Ivy

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Closure Compiler is a JavaScript optimizing compiler. It parses your JavaScript, analyzes it, removes dead code and rewrites and minimizes what's left. It also checks syntax, variable references, and types, and warns about common JavaScript pitfalls. It is used in many of Google's JavaScript apps, including Gmail, Google Web Search, Google Maps, and Google Docs. This binary checks for style issues such as incorrect or missing JSDoc usage, and missing goog.require() statements. It does not do more advanced checks such as typechecking.
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/*
 * Copyright 2015 The Closure Compiler Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.javascript.jscomp.lint;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;

import com.google.common.collect.Ordering;
import com.google.javascript.jscomp.AbstractCompiler;
import com.google.javascript.jscomp.DiagnosticType;
import com.google.javascript.jscomp.HotSwapCompilerPass;
import com.google.javascript.jscomp.JSError;
import com.google.javascript.jscomp.NodeTraversal;
import com.google.javascript.jscomp.NodeTraversal.AbstractShallowCallback;
import com.google.javascript.jscomp.NodeUtil;
import com.google.javascript.rhino.Node;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Checks that goog.require() and goog.provide() calls are sorted alphabetically.
 */
public final class CheckRequiresAndProvidesSorted extends AbstractShallowCallback
    implements HotSwapCompilerPass {
  public static final DiagnosticType REQUIRES_NOT_SORTED =
      DiagnosticType.warning(
          "JSC_REQUIRES_NOT_SORTED",
          "goog.require() and goog.requireType() statements are not sorted."
              + " The correct order is:\n\n{0}\n");

  public static final DiagnosticType PROVIDES_NOT_SORTED =
      DiagnosticType.warning(
          "JSC_PROVIDES_NOT_SORTED",
          "goog.provide() statements are not sorted."
              + " The correct order is:\n\n{0}\n");

  public static final DiagnosticType PROVIDES_AFTER_REQUIRES =
      DiagnosticType.warning(
          "JSC_PROVIDES_AFTER_REQUIRES",
          "goog.provide() statements should be before"
              + " goog.require() and goog.requireType() statements.");

  public static final DiagnosticType DUPLICATE_REQUIRE =
      DiagnosticType.warning("JSC_DUPLICATE_REQUIRE", "''{0}'' required more than once.");

  private final List requires;
  private final List provides;

  private final AbstractCompiler compiler;

  public CheckRequiresAndProvidesSorted(AbstractCompiler compiler) {
    this.compiler = compiler;
    this.requires = new ArrayList<>();
    this.provides = new ArrayList<>();
  }

  @Override
  public void process(Node externs, Node root) {
    NodeTraversal.traverse(compiler, root, this);
  }

  @Override
  public void hotSwapScript(Node scriptRoot, Node originalRoot) {
    NodeTraversal.traverse(compiler, scriptRoot, this);
  }

  public static final String getSortKey(Node n) {
    String key = null;
    boolean isForwardDeclare = false;
    if (NodeUtil.isNameDeclaration(n)) {
      if (n.getFirstChild().isName()) {
        // Case 1:
        //   var x = goog.require('w.x');
        // or
        //   var x = goog.forwardDeclare('w.x');
        key = n.getFirstChild().getString();
        if (n.getFirstFirstChild().getFirstChild().matchesQualifiedName("goog.forwardDeclare")) {
              isForwardDeclare = true;
            }
      } else if (n.getFirstChild().isDestructuringLhs()) {
        // Case 2: var {y} = goog.require('w.x');
        // All case 2 nodes should come after all case 1 nodes. ('{' sorts after a-z)
        Node pattern = n.getFirstFirstChild();
        checkState(pattern.isObjectPattern(), pattern);
        Node call = n.getFirstChild().getLastChild();
        checkState(call.isCall(), call);
        checkState(
            call.getFirstChild().matchesQualifiedName("goog.require")
                || call.getFirstChild().matchesQualifiedName("goog.requireType"),
            call.getFirstChild());
        if (!pattern.hasChildren()) {
          key = "{";
        } else {
          key = "{" + pattern.getFirstChild().getString();
        }
      }
    } else if (n.isExprResult()) {
      // Case 3, one of:
      //   goog.provide('a.b.c');
      //   goog.require('a.b.c');
      //   goog.forwardDeclare('a.b.c');
      // All case 3 nodes should come after case 1 and 2 nodes, so prepend
      // '|' which sorts after '{'
      key = "|" + n.getFirstChild().getLastChild().getString();
      if (n.getFirstFirstChild().matchesQualifiedName("goog.forwardDeclare")) {
        isForwardDeclare = true;
      }
    } else {
      throw new IllegalArgumentException("Unexpected node " + n);
    }
    // Make sure all forwardDeclares come after all requires.
    return (isForwardDeclare ? "z" : "a") + checkNotNull(key);
  }

  private static final String getNamespace(Node requireStatement) {
    if (requireStatement.isExprResult()) {
      // goog.require('a.b.c');
      return requireStatement.getFirstChild().getLastChild().getString();
    } else if (NodeUtil.isNameDeclaration(requireStatement)) {
      if (requireStatement.getFirstChild().isName()) {
        // const x = goog.require('a.b.c');
        return requireStatement.getFirstFirstChild().getLastChild().getString();
      } else if (requireStatement.getFirstChild().isDestructuringLhs()) {
        // const {x} = goog.require('a.b.c');
        return requireStatement.getFirstChild().getLastChild().getLastChild().getString();
      }
    }
    throw new IllegalArgumentException("Unexpected node " + requireStatement);
  }

  private final Ordering alphabetical =
      Ordering.natural().onResultOf(CheckRequiresAndProvidesSorted::getSortKey);

  @Override
  public void visit(NodeTraversal t, Node n, Node parent) {
    switch (n.getToken()) {
      case SCRIPT:
        // Duplicate provides are already checked in ProcessClosurePrimitives.
        checkForDuplicates(requires);
        reportIfOutOfOrder(requires, REQUIRES_NOT_SORTED);
        reportIfOutOfOrder(provides, PROVIDES_NOT_SORTED);
        reset();
        break;
      case CALL:
        Node callee = n.getFirstChild();
        if (!callee.matchesQualifiedName("goog.require")
            && !callee.matchesQualifiedName("goog.requireType")
            && !callee.matchesQualifiedName("goog.forwardDeclare")
            && !callee.matchesQualifiedName("goog.provide")
            && !callee.matchesQualifiedName("goog.module")) {
          return;
        }

        if (parent.isExprResult() && NodeUtil.isTopLevel(parent.getParent())) {
          Node namespaceNode = n.getLastChild();
          if (!namespaceNode.isString()) {
            return;
          }
          String namespace = namespaceNode.getString();
          if (namespace == null) {
            return;
          }
          if (callee.matchesQualifiedName("goog.require")
              || callee.matchesQualifiedName("goog.requireType")
              || callee.matchesQualifiedName("goog.forwardDeclare")) {
            requires.add(parent);
          } else {
            if (!requires.isEmpty()) {
              t.report(n, PROVIDES_AFTER_REQUIRES);
            }
            if (callee.matchesQualifiedName("goog.provide")) {
              provides.add(parent);
            }
          }
        } else if (NodeUtil.isNameDeclaration(parent.getParent())
            && (callee.matchesQualifiedName("goog.require")
                || callee.matchesQualifiedName("goog.requireType")
                || callee.matchesQualifiedName("goog.forwardDeclare"))) {
          requires.add(parent.getParent());
        }
        break;
      default:
        break;
    }
  }

  private void reportIfOutOfOrder(List requiresOrProvides, DiagnosticType warning) {
    if (!alphabetical.isOrdered(requiresOrProvides)) {
      StringBuilder correctOrder = new StringBuilder();
      for (Node n : alphabetical.sortedCopy(requiresOrProvides)) {
        correctOrder.append(compiler.toSource(n));
      }
      compiler.report(
          JSError.make(requiresOrProvides.get(0), warning, correctOrder.toString()));
    }
  }

  private void checkForDuplicates(List requires) {
    Set namespaces = new HashSet<>();
    for (Node require : requires) {
      String namespace = getNamespace(require);
      if (!namespaces.add(namespace)) {
        compiler.report(JSError.make(require, DUPLICATE_REQUIRE, namespace));
      }
    }
  }

  private void reset() {
    requires.clear();
    provides.clear();
  }
}