Add 'buf format'

package.json

@@ -2,7 +2,7 @@
 	"name": "vscode-buf",
 	"displayName": "Buf",
 	"description": "Visual Studio Code support for Buf",
-	"version": "0.4.0",
+	"version": "0.5.0",
 	"icon": "logo.png",
 	"publisher": "bufbuild",
 	"repository": {
@@ -23,6 +23,7 @@
 		"vscode": "^1.63.0"
 	},
 	"categories": [
+		"Formatters",
 		"Linters"
 	],
 	"keywords": [
@@ -31,6 +32,7 @@
 		"protobuf",
 		"protocol buffers",
 		"buf",
+		"bufbuild",
 		"lint"
 	],
 	"activationEvents": [
@@ -61,6 +63,11 @@
 				}
 			}
 		},
+		"configurationDefaults": {
+			"[proto]": {
+				"editor.formatOnSave": true
+			}
+		},
 		"languages": [
 			{
 				"id": "yaml",
@@ -70,6 +77,16 @@
 					"buf.work",
 					"buf.gen"
 				]
+			},
+			{
+				"id": "proto",
+				"extensions": [
+					".proto"
+				],
+				"aliases": [
+					"Protocol Buffers",
+					"Protobufs"
+				]
 			}
 		]
 	},

src/extension.ts

@@ -1,6 +1,7 @@
 import * as vscode from "vscode";
 import { downloadPage, lint, minimumVersion, version } from "./buf";
 import { isError } from "./errors";
+import { Formatter } from "./formatter";
 import { parseLines, Warning } from "./parser";
 import { format, less } from "./version";
 
@@ -124,6 +125,7 @@ export function activate(context: vscode.ExtensionContext) {
     diagnosticCollection.set(document.uri, diagnostics);
   };
 
+  context.subscriptions.push(vscode.languages.registerDocumentFormattingEditProvider('proto', new Formatter(binaryPath)));
   context.subscriptions.push(vscode.workspace.onDidSaveTextDocument(doLint));
   context.subscriptions.push(vscode.workspace.onDidOpenTextDocument(doLint));
   context.subscriptions.push(

src/formatter.ts

@@ -0,0 +1,78 @@
+import * as cp from "child_process";
+import * as os from "os";
+import * as path from "path";
+import * as vscode from "vscode";
+import { TextEncoder } from "util";
+
+export class Formatter implements vscode.DocumentFormattingEditProvider {
+    readonly binaryPath: string = '';
+
+    constructor(binaryPath: string) {
+        if (!binaryPath || binaryPath.length === 0) {
+            throw new Error('binaryPath is required to construct a formatter');
+        }
+        this.binaryPath = binaryPath;
+    }
+
+    public provideDocumentFormattingEdits(
+        document: vscode.TextDocument,
+        // @ts-ignore: The formatter doesn't have any options, but we need to implement the interface.
+        options: vscode.FormattingOptions,
+        token: vscode.CancellationToken
+    ): vscode.ProviderResult<vscode.TextEdit[]> {
+        if (vscode.window.visibleTextEditors.every((e) => e.document.fileName !== document.fileName)) {
+            return [];
+        }
+        return this.runFormatter(document, token).then(
+            (edits) => edits,
+            (err) => {
+                console.log(err);
+                return Promise.reject('Check the console in dev tools to find errors when formatting.');
+            }
+        );
+    }
+
+    private randomId(): string {
+        return (Math.floor(Math.random() * 100000)).toString()
+    }
+
+    private runFormatter(
+        document: vscode.TextDocument,
+        token: vscode.CancellationToken
+    ): Thenable<vscode.TextEdit[]> {
+        return new Promise<vscode.TextEdit[]>((resolve, reject) => {
+            const cwd = path.join(os.tmpdir(), this.randomId());
+            vscode.workspace.fs.createDirectory(vscode.Uri.file(cwd)).then(() => {
+                // Buf format expects a `.proto` file, so add unique id as a prefix.
+                const backupFile = path.join(cwd, this.randomId() + "-" + path.basename(document.fileName));
+                vscode.workspace.fs.writeFile(vscode.Uri.file(backupFile), new TextEncoder().encode(document.getText())).then(() => {
+                    let stdout = '';
+                    let stderr = '';
+
+                    const p = cp.spawn(this.binaryPath, ['format', backupFile], { cwd });
+                    token.onCancellationRequested(() => !p.killed && p.kill());
+
+                    p.stdout.setEncoding('utf8');
+                    p.stdout.on('data', (data: any) => (stdout += data));
+                    p.stderr.on('data', (data: any) => (stderr += data));
+                    p.on('error', (err: any) => {
+                        if (err && (<any>err).code === 'ENOENT') {
+                            return reject();
+                        }
+                    });
+                    p.on('close', (code: number) => {
+                        if (code !== 0) {
+                            return reject(stderr);
+                        }
+                        const fileStart = new vscode.Position(0, 0);
+                        const fileEnd = document.lineAt(document.lineCount - 1).range.end;
+                        const textEdits: vscode.TextEdit[] = [
+                            new vscode.TextEdit(new vscode.Range(fileStart, fileEnd), stdout)
+                        ];
+                        return resolve(textEdits);
+                    });
+                });
+            });
+        });
+    }
+}