agentHost: complete skills after whitespace

src/vs/platform/agentHost/node/agentHostSkillCompletionProvider.ts

@@ -11,7 +11,7 @@ import { CompletionItem, CompletionItemKind, CompletionsParams } from '../common
 import { MessageAttachmentKind } from '../common/state/protocol/state.js';
 import { CustomizationType, SkillCustomization } from '../common/state/sessionState.js';
 import { CompletionTriggerCharacter, IAgentHostCompletionItemProvider } from './agentHostCompletions.js';
-import { extractLeadingSlashToken } from './agentHostSlashCompletion.js';
+import { extractWhitespaceDelimitedSlashToken } from './agentHostSlashCompletion.js';
 
 /**
  * Generic completion provider that contributes slash completions for skills
@@ -29,7 +29,7 @@ export class AgentHostSkillCompletionProvider extends Disposable implements IAge
 	}
 
 	async provideCompletionItems(params: CompletionsParams, token: CancellationToken): Promise<readonly CompletionItem[]> {
-		const leading = extractLeadingSlashToken(params.text, params.offset);
+		const leading = extractWhitespaceDelimitedSlashToken(params.text, params.offset);
 		if (!leading) {
 			return [];
 		}

src/vs/platform/agentHost/node/agentHostSlashCompletion.ts

@@ -28,8 +28,7 @@ export function extractLeadingSlashToken(text: string, offset: number): ILeading
 	}
 	let end = 1;
 	while (end < text.length) {
-		const ch = text.charCodeAt(end);
-		if (ch === 0x20 /* space */ || ch === 0x09 /* tab */ || ch === 0x0a /* \n */ || ch === 0x0d /* \r */) {
+		if (isSlashTokenWhitespace(text.charCodeAt(end))) {
 			break;
 		}
 		end++;
@@ -39,4 +38,37 @@ export function extractLeadingSlashToken(text: string, offset: number): ILeading
 	}
 	const token = text.slice(0, end);
 	return { token, typed: token.slice(1), rangeStart: 0, rangeEnd: end };
-}
+}
+
+/**
+ * Extracts the slash token containing the cursor when the slash is either at
+ * the start of the input or immediately follows whitespace.
+ */
+export function extractWhitespaceDelimitedSlashToken(text: string, offset: number): ILeadingSlashToken | undefined {
+	if (text.length === 0 || offset < 0 || offset > text.length) {
+		return undefined;
+	}
+
+	let start = offset;
+	while (start > 0 && !isSlashTokenWhitespace(text.charCodeAt(start - 1))) {
+		start--;
+	}
+	if (start >= text.length || text.charCodeAt(start) !== 0x2f /* / */) {
+		return undefined;
+	}
+
+	let end = start + 1;
+	while (end < text.length && !isSlashTokenWhitespace(text.charCodeAt(end))) {
+		end++;
+	}
+	if (offset > end) {
+		return undefined;
+	}
+
+	const token = text.slice(start, end);
+	return { token, typed: token.slice(1), rangeStart: start, rangeEnd: end };
+}
+
+function isSlashTokenWhitespace(ch: number): boolean {
+	return ch === 0x20 /* space */ || ch === 0x09 /* tab */ || ch === 0x0a /* \n */ || ch === 0x0d /* \r */;
+}

src/vs/platform/agentHost/test/node/agentHostSkillCompletionProvider.test.ts

@@ -136,6 +136,54 @@ suite('AgentHostSkillCompletionProvider', () => {
 		]);
 	});
 
+	test('filters skills by an in-message slash prefix and replaces only that token', async () => {
+		const agent = new MockAgent('mock');
+		agent.getSessionCustomizations = async () => [plugin('skills', [skill('alpha'), skill('beta')])];
+		const provider = createProvider(agent);
+		const text = 'use /b extra';
+
+		const result = await run(provider, text, text.indexOf('/b') + '/b'.length);
+
+		assert.deepStrictEqual(result.map(item => ({ insertText: item.insertText, rangeStart: item.rangeStart, rangeEnd: item.rangeEnd })), [
+			{ insertText: '/beta ', rangeStart: 4, rangeEnd: 6 },
+		]);
+	});
+
+	test('returns skills for a slash token after whitespace', async () => {
+		const agent = new MockAgent('mock');
+		agent.getSessionCustomizations = async () => [plugin('skills', [skill('alpha'), skill('beta')])];
+		const provider = createProvider(agent);
+		const text = 'use /';
+
+		const result = await run(provider, text);
+
+		assert.deepStrictEqual(result.map(item => ({ insertText: item.insertText, rangeStart: item.rangeStart, rangeEnd: item.rangeEnd })), [
+			{ insertText: '/alpha ', rangeStart: 4, rangeEnd: 5 },
+			{ insertText: '/beta ', rangeStart: 4, rangeEnd: 5 },
+		]);
+	});
+
+	test('does not complete slash tokens embedded in non-whitespace text', async () => {
+		const agent = new MockAgent('mock');
+		agent.getSessionCustomizations = async () => [plugin('skills', [skill('alpha')])];
+		const provider = createProvider(agent);
+
+		const result = await run(provider, 'foo/bar', 'foo/bar'.length);
+
+		assert.deepStrictEqual(result, []);
+	});
+
+	test('returns an empty list when the cursor is past an in-message slash token', async () => {
+		const agent = new MockAgent('mock');
+		agent.getSessionCustomizations = async () => [plugin('skills', [skill('cached-skill')])];
+		const provider = createProvider(agent);
+		const text = 'use /cached-skill trailing';
+
+		const result = await run(provider, text, text.indexOf('trailing'));
+
+		assert.deepStrictEqual(result, []);
+	});
+
 	test('returns an empty list when the cursor is past the leading slash token', async () => {
 		const agent = new MockAgent('mock');
 		agent.getSessionCustomizations = async () => [plugin('skills', [skill('cached-skill')])];