Enable client snippet before the language server is ready (#1101)

Signed-off-by: Sheng Chen <sheche@microsoft.com>

Author: jdneo

package-lock.json

@@ -545,6 +545,7 @@
     "tslint": "tslint -p ."
   },
   "devDependencies": {
+    "@types/fs-extra": "^8.0.0",
     "@types/glob": "5.0.30",
     "@types/lodash.findindex": "^4.6.6",
     "@types/mocha": "^5.2.5",
@@ -571,6 +572,7 @@
     "tmp": "^0.0.33",
     "path-exists": "^3.0.0",
     "expand-home-dir": "^0.0.3",
+    "fs-extra": "^8.1.0",
     "glob": "^7.1.3",
     "winston": "^3.2.1",
     "winston-daily-rotate-file": "^3.10.0"

package.json

@@ -0,0 +1,90 @@
+{
+	"sysout": {
+		"prefix": "sysout",
+		"body": [
+			"System.out.println($0);"
+		],
+		"description": "Print to standard out"
+	},
+	"syserr": {
+		"prefix": "syserr",
+		"body": [
+			"System.err.println($0);"
+		],
+		"description": "Print to standard err"
+	},
+	"fori": {
+		"prefix": "fori",
+		"body": [
+			"for (${1:int} ${2:i} = ${3:0}; ${2:i} < ${4:max}; ${2:i}++) {",
+			"\t$0",
+			"}"
+		],
+		"description": "Indexed for loop"
+	},
+	"foreach": {
+		"prefix": "foreach",
+		"body": [
+			"for (${1:type} ${2:var} : ${3:iterable}) {",
+			"\t$0",
+			"}"
+		],
+		"description": "Enhanced for loop"
+	},
+	"if": {
+		"prefix": "if",
+		"body": [
+			"if (${1:condition}) {",
+			"\t$0",
+			"}"
+		],
+		"description": "if statement"
+	},
+	"ifelse": {
+		"prefix": "ifelse",
+		"body": [
+			"if (${1:condition}) {",
+			"\t$2",
+			"} else {",
+			"\t$0",
+			"}"
+		],
+		"description": "if/else statement"
+	},
+	"ifnull": {
+		"prefix": "ifnull",
+		"body": [
+			"if (${1:condition} == null) {",
+			"\t$0",
+			"}"
+		],
+		"description": "if statement checking for null"
+	},
+	"ifnotnull": {
+		"prefix": "ifnotnull",
+		"body": [
+			"if (${1:condition} != null) {",
+			"\t$0",
+			"}"
+		],
+		"description": "if statement checking for not null"
+	},
+	"While Statement": {
+		"prefix": "while",
+		"body": [
+			"while (${1:condition}) {",
+			"\t$0",
+			"}"
+		],
+		"description": "While Statement"
+	},
+	"Do-While Statement": {
+		"prefix": "dowhile",
+		"body": [
+			"do {",
+			"\t$0",
+			"} while (${1:condition});"
+		],
+		"description": "Do-While Statement"
+	}
+}

snippets/server.json

@@ -25,6 +25,7 @@ import { getJavaConfiguration } from './utils';
 import { onConfigurationChange, excludeProjectSettingsFiles } from './settings';
 import { logger, initializeLogFile } from './log';
 import glob = require('glob');
+import { SnippetCompletionProvider } from './snippetCompletionProvider';
 import { serverTasks } from './serverTasks';
 import { serverTaskPresenter } from './serverTaskPresenter';
 import { serverStatus, ServerStatusKind } from './serverStatus';
@@ -224,6 +225,9 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 			const registerHoverCommand = hoverAction.registerClientHoverProvider(languageClient, context);
 			const getDocumentSymbols: getDocumentSymbolsCommand = getDocumentSymbolsProvider(languageClient);
 
+			const snippetProvider: SnippetCompletionProvider = new SnippetCompletionProvider();
+			context.subscriptions.push(languages.registerCompletionItemProvider({ scheme: 'file', language: 'java' }, snippetProvider));
+
 			languageClient.onReady().then(() => {
 				languageClient.onNotification(StatusNotification.type, (report) => {
 					switch (report.type) {
@@ -237,6 +241,7 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 								registerHoverCommand,
 								getDocumentSymbols
 							});
+							snippetProvider.setActivation(false);
 							break;
 						case 'Error':
 							serverStatus.updateServerStatus(ServerStatusKind.Error);

src/extension.ts

@@ -0,0 +1,44 @@
+'use strict';
+
+import { CompletionItemProvider, TextDocument, Position, CancellationToken, CompletionContext, CompletionItem, CompletionItemKind, SnippetString, MarkdownString } from "vscode";
+import * as fse from 'fs-extra';
+import * as path from 'path';
+
+export class SnippetCompletionProvider implements CompletionItemProvider {
+
+    private snippets: {};
+    private activation: boolean;
+
+    public constructor() {
+        this.activation = true;
+        this.snippets = fse.readJSONSync(path.join(__dirname, '..', 'snippets', 'server.json'));
+    }
+
+    public async provideCompletionItems(_document: TextDocument, _position: Position, _token: CancellationToken, _context: CompletionContext): Promise<CompletionItem[]> {
+        if (!this.activation) {
+            return [];
+        }
+
+        const snippetItems: CompletionItem[] = [];
+        for (const label of Object.keys(this.snippets)) {
+            const snippetContent = this.snippets[label];
+            const snippetItem: CompletionItem = new CompletionItem(snippetContent.prefix);
+            snippetItem.kind = CompletionItemKind.Snippet;
+            snippetItem.detail = snippetContent.description;
+            const insertText: string = (snippetContent.body as String[]).join('\n');
+            snippetItem.insertText = new SnippetString(insertText);
+            snippetItem.documentation = beautifyDocument(insertText);
+            snippetItems.push(snippetItem);
+        }
+        return snippetItems;
+    }
+
+    public setActivation(activation: boolean): void {
+        this.activation = activation;
+    }
+}
+
+export function beautifyDocument(raw: string): MarkdownString {
+    const escapedString = raw.replace(/\$\{\d:?(.*?)\}/gm, '$1').replace(/\$\d/gm, '');
+    return new MarkdownString().appendCodeblock(escapedString, "java");
+}

src/snippetCompletionProvider.ts

@@ -0,0 +1,14 @@
+import * as assert from 'assert';
+import { beautifyDocument } from '../src/snippetCompletionProvider';
+import { MarkdownString } from 'vscode';
+
+suite('Snippet Completion Provider', () => {
+
+	test('should render document correctly', () => {
+		// tslint:disable: prefer-template
+		const raw = "for (${1:int} ${2:i} = ${3:0}; ${2:i} < ${4:max}; ${2:i}++) {\n" + "\t$0\n" + "}";
+		const markdownString: MarkdownString = beautifyDocument(raw);
+		const expected: string = "\n```java\n" + "for (int i = 0; i < max; i++) {\n" + "\t\n" + "}\n" + "```\n";
+		assert.equal(markdownString.value, expected);
+	});
+});