know when a snippet needs clipboard access, #76847

src/vs/workbench/contrib/snippets/browser/snippetCompletionProvider.ts

@@ -32,7 +32,7 @@ export class SnippetCompletion implements CompletionItem {
 	) {
 		this.label = snippet.prefix;
 		this.detail = localize('detail.snippet', "{0} ({1})", snippet.description || snippet.name, snippet.source);
-		this.insertText = snippet.body;
+		this.insertText = snippet.codeSnippet;
 		this.range = range;
 		this.sortText = `${snippet.snippetSource === SnippetSource.Extension ? 'z' : 'a'}-${snippet.prefix}`;
 		this.kind = CompletionItemKind.Snippet;
@@ -41,7 +41,6 @@ export class SnippetCompletion implements CompletionItem {
 
 	resolve(): this {
 		this.documentation = new MarkdownString().appendCodeblock('', new SnippetParser().text(this.snippet.codeSnippet));
-		this.insertText = this.snippet.codeSnippet;
 		return this;
 	}
 

src/vs/workbench/contrib/snippets/browser/snippetsFile.ts

@@ -13,11 +13,67 @@ import { isFalsyOrWhitespace } from 'vs/base/common/strings';
 import { URI } from 'vs/base/common/uri';
 import { IFileService } from 'vs/platform/files/common/files';
 import { IExtensionDescription } from 'vs/platform/extensions/common/extensions';
+import { IdleValue } from 'vs/base/common/async';
+
+class SnippetBodyInsights {
+
+	readonly codeSnippet: string;
+	readonly isBogous: boolean;
+	readonly needsClipboard: boolean;
+
+	constructor(body: string) {
+
+		// init with defaults
+		this.isBogous = false;
+		this.needsClipboard = false;
+		this.codeSnippet = body;
+
+		// check snippet...
+		const textmateSnippet = new SnippetParser().parse(body, false);
+
+		let placeholders = new Map<string, number>();
+		let placeholderMax = 0;
+		for (const placeholder of textmateSnippet.placeholders) {
+			placeholderMax = Math.max(placeholderMax, placeholder.index);
+		}
+
+		let stack = [...textmateSnippet.children];
+		while (stack.length > 0) {
+			const marker = stack.shift()!;
+			if (marker instanceof Variable) {
+
+				if (marker.children.length === 0 && !KnownSnippetVariableNames[marker.name]) {
+					// a 'variable' without a default value and not being one of our supported
+					// variables is automatically turned into a placeholder. This is to restore
+					// a bug we had before. So `${foo}` becomes `${N:foo}`
+					const index = placeholders.has(marker.name) ? placeholders.get(marker.name)! : ++placeholderMax;
+					placeholders.set(marker.name, index);
+
+					const synthetic = new Placeholder(index).appendChild(new Text(marker.name));
+					textmateSnippet.replace(marker, [synthetic]);
+					this.isBogous = true;
+				}
+
+				if (marker.name === 'CLIPBOARD') {
+					this.needsClipboard = true;
+				}
+
+			} else {
+				// recurse
+				stack.push(...marker.children);
+			}
+		}
+
+		if (this.isBogous) {
+			this.codeSnippet = textmateSnippet.toTextmateString();
+		}
+
+	}
+}
 
 export class Snippet {
 
-	private _codeSnippet: string;
-	private _isBogous: boolean;
+	private readonly _bodyInsights: IdleValue<SnippetBodyInsights>;
 
 	readonly prefixLow: string;
 
@@ -32,29 +88,19 @@ export class Snippet {
 	) {
 		//
 		this.prefixLow = prefix ? prefix.toLowerCase() : prefix;
+		this._bodyInsights = new IdleValue(() => new SnippetBodyInsights(this.body));
 	}
 
 	get codeSnippet(): string {
-		this._ensureCodeSnippet();
-		return this._codeSnippet;
+		return this._bodyInsights.getValue().codeSnippet;
 	}
 
 	get isBogous(): boolean {
-		this._ensureCodeSnippet();
-		return this._isBogous;
+		return this._bodyInsights.getValue().isBogous;
 	}
 
-	private _ensureCodeSnippet() {
-		if (!this._codeSnippet) {
-			const rewrite = Snippet._rewriteBogousVariables(this.body);
-			if (typeof rewrite === 'string') {
-				this._codeSnippet = rewrite;
-				this._isBogous = true;
-			} else {
-				this._codeSnippet = this.body;
-				this._isBogous = false;
-			}
-		}
+	get needsClipboard(): boolean {
+		return this._bodyInsights.getValue().needsClipboard;
 	}
 
 	static compare(a: Snippet, b: Snippet): number {
@@ -70,49 +116,6 @@ export class Snippet {
 			return 0;
 		}
 	}
-
-	static _rewriteBogousVariables(template: string): false | string {
-		const textmateSnippet = new SnippetParser().parse(template, false);
-
-		let placeholders = new Map<string, number>();
-		let placeholderMax = 0;
-		for (const placeholder of textmateSnippet.placeholders) {
-			placeholderMax = Math.max(placeholderMax, placeholder.index);
-		}
-
-		let didChange = false;
-		let stack = [...textmateSnippet.children];
-
-		while (stack.length > 0) {
-			const marker = stack.shift()!;
-
-			if (
-				marker instanceof Variable
-				&& marker.children.length === 0
-				&& !KnownSnippetVariableNames[marker.name]
-			) {
-				// a 'variable' without a default value and not being one of our supported
-				// variables is automatically turned into a placeholder. This is to restore
-				// a bug we had before. So `${foo}` becomes `${N:foo}`
-				const index = placeholders.has(marker.name) ? placeholders.get(marker.name)! : ++placeholderMax;
-				placeholders.set(marker.name, index);
-
-				const synthetic = new Placeholder(index).appendChild(new Text(marker.name));
-				textmateSnippet.replace(marker, [synthetic]);
-				didChange = true;
-
-			} else {
-				// recurse
-				stack.push(...marker.children);
-			}
-		}
-
-		if (!didChange) {
-			return false;
-		} else {
-			return textmateSnippet.toTextmateString();
-		}
-	}
 }
 
 

src/vs/workbench/contrib/snippets/test/browser/snippetFile.test.ts

@@ -65,4 +65,19 @@ suite('Snippets', function () {
 
 	});
 
+	test('Snippet#needsClipboard', function () {
+
+		function assertNeedsClipboard(body: string, expected: boolean): void {
+			let snippet = new Snippet(['foo'], 'FooSnippet1', 'foo', '', body, 'test', SnippetSource.User);
+			assert.equal(snippet.needsClipboard, expected);
+		}
+
+		assertNeedsClipboard('foo$CLIPBOARD', true);
+		assertNeedsClipboard('${CLIPBOARD}', true);
+		assertNeedsClipboard('foo${CLIPBOARD}bar', true);
+		assertNeedsClipboard('foo$clipboard', false);
+		assertNeedsClipboard('foo${clipboard}', false);
+		assertNeedsClipboard('baba', false);
+	});
+
 });

src/vs/workbench/contrib/snippets/test/browser/snippetsRewrite.test.ts

@@ -9,8 +9,12 @@ import { Snippet, SnippetSource } from 'vs/workbench/contrib/snippets/browser/sn
 suite('SnippetRewrite', function () {
 
 	function assertRewrite(input: string, expected: string | boolean): void {
-		const actual = Snippet._rewriteBogousVariables(input);
-		assert.equal(actual, expected);
+		const actual = new Snippet(['foo'], 'foo', 'foo', 'foo', input, 'foo', SnippetSource.User);
+		if (typeof expected === 'boolean') {
+			assert.equal(actual.codeSnippet, input);
+		} else {
+			assert.equal(actual.codeSnippet, expected);
+		}
 	}
 
 	test('bogous variable rewrite', function () {