added support for buildifier auto-formating on save

Author: lonhutt

package.json

@@ -57,20 +57,46 @@
 			{
 				"id": "bazelproject",
 				"aliases": [
-					"bazelproject",
 					"bazelproject"
 				],
 				"extensions": [
 					".bazelproject"
 				],
 				"configuration": "./syntaxes/bazelproject-language-configuration.json"
+			},
+			{
+				"id": "starlark",
+				"aliases": [
+					"Starlark",
+					"starlark",
+					"Bazel"
+				],
+				"extensions": [
+					".BUILD",
+					".WORKSPACE",
+					".bazel",
+					".bzl",
+					".bzlmod",
+					".sky",
+					".star"
+				],
+				"filenames": [
+					"BUILD",
+					"WORKSPACE"
+				],
+				"configuration": "./syntaxes/starlark-language-configuration.json"
 			}
 		],
 		"grammars": [
 			{
 				"language": "bazelproject",
 				"scopeName": "source.bazelproject",
 				"path": "./syntaxes/bazelproject.tmLanguage.json"
+			},
+			{
+				"language": "starlark",
+				"scopeName": "source.starlark",
+				"path": "./syntaxes/starlark.tmLanguage.json"
 			}
 		],
 		"taskDefinitions": [
@@ -131,6 +157,18 @@
 					"default": true,
 					"description": "Display 'sync project view' notification info window on .bazelproject edit",
 					"scope": "window"
+				},
+				"bazel.buildifier.enable": {
+					"type": "boolean",
+					"default": true,
+					"description": "Enable buildifier formatting tool on save",
+					"scope": "window"
+				},
+				"bazel.buildifier.binary": {
+					"type": ["string", "null"],
+					"default": null,
+					"description": "path to buildifier binary. If not set buildifier from your PATH will be used",
+					"scope": "window"
 				}
 			}
 		},
@@ -270,7 +308,7 @@
 		"esbuild:watch": "npm run esbuild:base -- --sourcemap --watch",
 		"analyze": "npm run esbuild:base -- --minify --metafile --analyze && esbuild-visualizer --metadata ./meta.json --open",
 		"lint": "eslint src --ext ts",
-		"lint:fix" : "eslint src --ext ts --fix",
+		"lint:fix": "eslint src --ext ts --fix",
 		"test": "run-s clean test:*",
 		"test:compile": "tsc -b ./test/tsconfig.json",
 		"test:lint": "eslint --ext .js,.ts,.tsx src",

src/buildifier.ts

@@ -0,0 +1,99 @@
+import { exec } from 'child_process';
+import {
+	languages,
+	Range,
+	TextDocument,
+	TextEdit,
+	window,
+	workspace,
+} from 'vscode';
+import { getWorkspaceRoot } from './util';
+
+export function registerBuildifierFormatter() {
+	languages.registerDocumentFormattingEditProvider(
+		{ scheme: 'file', language: 'starlark' },
+		{
+			async provideDocumentFormattingEdits(
+				document: TextDocument
+			): Promise<TextEdit[]> {
+				if (
+					workspace.getConfiguration('bazel.buildifier').get('enable', false)
+				) {
+					try {
+						if (await buildifierExists()) {
+							const updatedContent = await runBuildifier(document.fileName);
+
+							// only return an edit if there is a value in `updatedContent`
+							return !!updatedContent
+								? [
+										TextEdit.replace(
+											new Range(
+												0,
+												0,
+												document.lineCount - 1,
+												document.lineAt(
+													document.lineCount - 1
+												).rangeIncludingLineBreak.end.character
+											),
+											updatedContent
+										),
+									]
+								: [];
+						}
+					} catch (err) {
+						window.showErrorMessage(`${err}`);
+						return [];
+					}
+				}
+
+				return [];
+			},
+		}
+	);
+}
+
+function buildifierExists(): Promise<boolean> {
+	return new Promise((resolve, reject) => {
+		exec(
+			`${getBuildifierCmd()} -version`,
+			{ cwd: getWorkspaceRoot() },
+			(err, stdout, stderr) => {
+				if (err) {
+					return reject(err);
+				}
+				return resolve(!stderr);
+			}
+		);
+	});
+}
+
+/**
+ * Utility function used to fetch the formatted text from the `buildifier`
+ * cmd. Uses `exec` since we want to get all of the cmd response in a single
+ * text blob
+ * @param bazelFile
+ * @returns
+ */
+function runBuildifier(bazelFile: string): Promise<string> {
+	return new Promise((resolve, reject) => {
+		exec(
+			`${getBuildifierCmd()} -mode print_if_changed ${workspace.asRelativePath(bazelFile)}`,
+			{
+				cwd: getWorkspaceRoot(),
+			},
+			(err, stdout, stderr) => {
+				if (err) {
+					console.error(stderr);
+					return reject(err);
+				}
+				return resolve(stdout);
+			}
+		);
+	});
+}
+
+function getBuildifierCmd(): string {
+	return workspace.getConfiguration('bazel.buildifier').get('binary')
+		? workspace.getConfiguration('bazel.buildifier').get('binary', 'buildifier')
+		: 'buildifier';
+}

src/extension.ts

@@ -15,6 +15,7 @@ import {
 	getBazelTerminal,
 } from './bazelLangaugeServerTerminal';
 import { BazelTaskManager } from './bazelTaskManager';
+import { registerBuildifierFormatter } from './buildifier';
 import { Commands, executeJavaLanguageServerCommand } from './commands';
 import { registerLSClient } from './loggingTCPServer';
 import { ProjectViewManager } from './projectViewManager';
@@ -27,7 +28,6 @@ import {
 } from './util';
 
 const workspaceRoot = getWorkspaceRoot();
-const workspaceRootName = workspaceRoot.split('/').reverse()[0];
 
 export async function activate(context: ExtensionContext) {
 	// activates
@@ -124,6 +124,8 @@ export async function activate(context: ExtensionContext) {
 		)
 	);
 
+	registerBuildifierFormatter();
+
 	// trigger a refresh of the tree view when any task get executed
 	tasks.onDidStartTask((_) => BazelRunTargetProvider.instance.refresh());
 	tasks.onDidEndTask((_) => BazelRunTargetProvider.instance.refresh());

syntaxes/starlark-language-configuration.json

@@ -0,0 +1,32 @@
+{
+    "comments": {
+        "lineComment": "#"
+    },
+    "brackets": [
+        ["{", "}"],
+        ["[", "]"],
+        ["(", ")"]
+    ],
+    "autoClosingPairs": [
+        ["{", "}"],
+        ["[", "]"],
+        ["(", ")"],
+        {
+            "open": "\"",
+            "close": "\"",
+            "notIn": ["string", "comment"]
+        },
+        {
+            "open": "'",
+            "close": "'",
+            "notIn": ["string", "comment"]
+        }
+    ],
+    "surroundingPairs": [
+        ["{", "}"],
+        ["[", "]"],
+        ["(", ")"],
+        ["\"", "\""],
+        ["'", "'"]
+    ]
+}