Code completion (review comments addressed)

src/completion-provider/bazel_completion_provider.ts

@@ -0,0 +1,126 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// 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.
+
+import * as vscode from "vscode";
+import { queryQuickPickTargets } from "../bazel";
+
+function insertCompletionItemIfUnique(
+  options: vscode.CompletionItem[],
+  option: vscode.CompletionItem,
+) {
+  if (
+    options.find((value: vscode.CompletionItem) => {
+      return value.label === option.label && value.kind === option.kind;
+    }) === undefined
+  ) {
+    options.push(option);
+  }
+}
+
+function getCandidateTargetFromDocumentPosition(
+  document: vscode.TextDocument,
+  position: vscode.Position,
+): string | undefined {
+  const linePrefix = document
+    .lineAt(position)
+    .text.substr(0, position.character);
+  const index = linePrefix.indexOf('"//');
+  if (index === -1) {
+    return undefined;
+  }
+  return linePrefix.substring(index + 1);
+}
+
+function stripLastPackageOrTargetName(target: string) {
+  const slashIndex = target.lastIndexOf("/");
+  const colonIndex = target.lastIndexOf(":");
+  const index = Math.max(slashIndex, colonIndex);
+  if (index !== -1) {
+    target = target.substring(0, index + 1);
+  }
+  return target;
+}
+
+function getNextPackage(target: string) {
+  const nextPackage = target.split("/", 2);
+  if (nextPackage.length > 1) {
+    return nextPackage[0];
+  } else if (nextPackage[0] !== "") {
+    const withoutTarget = nextPackage[0].split(":", 2);
+    if (withoutTarget.length > 1) {
+      return withoutTarget[0];
+    }
+  }
+  return undefined;
+}
+
+export class BazelCompletionItemProvider
+  implements vscode.CompletionItemProvider {
+  private targets: string[] = [];
+
+  /**
+   * Returns completion items matching the given prefix.
+   *
+   * Only label started with "//: is supported at the moment.
+   */
+  public provideCompletionItems(
+    document: vscode.TextDocument,
+    position: vscode.Position,
+  ) {
+    let candidateTarget = getCandidateTargetFromDocumentPosition(
+      document,
+      position,
+    );
+    if (candidateTarget === undefined) {
+      return [];
+    }
+
+    if (!candidateTarget.endsWith("/") && !candidateTarget.endsWith(":")) {
+      candidateTarget = stripLastPackageOrTargetName(candidateTarget);
+    }
+
+    const completionItems = new Array<vscode.CompletionItem>();
+    this.targets.forEach((target) => {
+      if (!target.startsWith(candidateTarget)) {
+        return;
+      }
+      const sufix = target.replace(candidateTarget, "");
+
+      let completionKind = vscode.CompletionItemKind.Folder;
+      let label = getNextPackage(sufix);
+      if (label === undefined) {
+        completionKind = vscode.CompletionItemKind.Field;
+        label = sufix;
+      }
+      insertCompletionItemIfUnique(
+        completionItems,
+        new vscode.CompletionItem(label, completionKind),
+      );
+    });
+    return completionItems;
+  }
+
+  /**
+   * Runs a bazel query command to acquire labels of all the targets in the
+   * workspace.
+   */
+  public async refresh() {
+    const queryTargets = await queryQuickPickTargets("kind('.* rule', ...)");
+    if (queryTargets.length !== 0) {
+      this.targets = queryTargets.map((queryTarget) => {
+        return queryTarget.label;
+      });
+    }
+  }
+}

src/completion-provider/index.ts

@@ -0,0 +1,15 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// 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.
+
+export * from "./bazel_completion_provider";

src/extension/extension.ts

@@ -32,6 +32,7 @@ import {
   checkBuildifierIsAvailable,
 } from "../buildifier";
 import { BazelBuildCodeLensProvider } from "../codelens";
+import { BazelCompletionItemProvider } from "../completion-provider";
 import { BazelTargetSymbolProvider } from "../symbols";
 import { BazelWorkspaceTreeProvider } from "../workspace-tree";
 import { getDefaultBazelExecutablePath } from "./configuration";
@@ -46,8 +47,17 @@ export function activate(context: vscode.ExtensionContext) {
   const workspaceTreeProvider = new BazelWorkspaceTreeProvider(context);
   const codeLensProvider = new BazelBuildCodeLensProvider(context);
   const buildifierDiagnostics = new BuildifierDiagnosticsManager();
+  const completionItemProvider = new BazelCompletionItemProvider();
+
+  completionItemProvider.refresh();
 
   context.subscriptions.push(
+    vscode.languages.registerCompletionItemProvider(
+      [{ pattern: "**/BUILD" }, { pattern: "**/BUILD.bazel" }],
+      completionItemProvider,
+      "/",
+      ":",
+    ),
     vscode.window.registerTreeDataProvider(
       "bazelWorkspace",
       workspaceTreeProvider,
@@ -71,6 +81,7 @@ export function activate(context: vscode.ExtensionContext) {
     ),
     vscode.commands.registerCommand("bazel.clean", bazelClean),
     vscode.commands.registerCommand("bazel.refreshBazelBuildTargets", () => {
+      completionItemProvider.refresh();
       workspaceTreeProvider.refresh();
     }),
     vscode.commands.registerCommand(
@@ -173,7 +184,9 @@ async function bazelBuildTargetWithDebugging(
     }
     return;
   }
-  const bazelConfigCmdLine = vscode.workspace.getConfiguration("bazel.commandLine");
+  const bazelConfigCmdLine = vscode.workspace.getConfiguration(
+    "bazel.commandLine",
+  );
   const startupOptions = bazelConfigCmdLine.get<string[]>("startupOptions");
   const commandArgs = bazelConfigCmdLine.get<string[]>("commandArgs");
 
@@ -412,9 +425,7 @@ function onTaskProcessEnd(event: vscode.TaskProcessEndEvent) {
     } else {
       const timeInSeconds = measurePerformance(bazelTaskInfo.startTime);
       vscode.window.showInformationMessage(
-        `Bazel ${
-          bazelTaskInfo.command
-        } completed successfully in ${timeInSeconds} seconds.`,
+        `Bazel ${bazelTaskInfo.command} completed successfully in ${timeInSeconds} seconds.`,
       );
     }
   }