Don't show suggestions for agent subcommand in an invalid spot after other text

src/vs/workbench/contrib/chat/browser/contrib/chatInputEditorContrib.ts

@@ -374,8 +374,8 @@ class AgentCompletions extends Disposable {
 				}
 
 				const parsedRequest = (await this.instantiationService.createInstance(ChatRequestParser).parseChatRequest(widget.viewModel.sessionId, model.getValue())).parts;
-				const usedAgent = parsedRequest.find((p): p is ChatRequestAgentPart => p instanceof ChatRequestAgentPart);
-				if (!usedAgent) {
+				const usedAgentIdx = parsedRequest.findIndex((p): p is ChatRequestAgentPart => p instanceof ChatRequestAgentPart);
+				if (usedAgentIdx < 0) {
 					return;
 				}
 
@@ -385,6 +385,14 @@ class AgentCompletions extends Disposable {
 					return;
 				}
 
+				for (const partAfterAgent of parsedRequest.slice(usedAgentIdx + 1)) {
+					if (!(partAfterAgent instanceof ChatRequestTextPart) || !partAfterAgent.text.match(/^\s+(\/\w*)?$/)) {
+						// No text allowed between agent and subcommand
+						return;
+					}
+				}
+
+				const usedAgent = parsedRequest[usedAgentIdx] as ChatRequestAgentPart;
 				const commands = await usedAgent.agent.provideSlashCommands(token);
 
 				return <CompletionList>{

src/vs/workbench/contrib/chat/common/chatRequestParser.ts

@@ -7,7 +7,7 @@ import { CancellationToken } from 'vs/base/common/cancellation';
 import { OffsetRange } from 'vs/editor/common/core/offsetRange';
 import { IPosition, Position } from 'vs/editor/common/core/position';
 import { Range } from 'vs/editor/common/core/range';
-import { IChatAgent, IChatAgentService } from 'vs/workbench/contrib/chat/common/chatAgents';
+import { IChatAgentService } from 'vs/workbench/contrib/chat/common/chatAgents';
 import { ChatRequestAgentPart, ChatRequestAgentSubcommandPart, ChatRequestDynamicReferencePart, ChatRequestSlashCommandPart, ChatRequestTextPart, ChatRequestVariablePart, IParsedChatRequest, IParsedChatRequestPart, chatVariableLeader } from 'vs/workbench/contrib/chat/common/chatParserTypes';
 import { IChatService } from 'vs/workbench/contrib/chat/common/chatService';
 import { IChatVariablesService } from 'vs/workbench/contrib/chat/common/chatVariables';
@@ -33,14 +33,14 @@ export class ChatRequestParser {
 			const previousChar = message.charAt(i - 1);
 			const char = message.charAt(i);
 			let newPart: IParsedChatRequestPart | undefined;
-			if (previousChar === ' ' || i === 0) {
+			if (previousChar.match(/\s/) || i === 0) {
 				if (char === chatVariableLeader) {
 					newPart = this.tryToParseVariable(message.slice(i), i, new Position(lineNumber, column), parts);
 				} else if (char === '@') {
-					newPart = this.tryToParseAgent(message.slice(i), i, new Position(lineNumber, column), parts);
+					newPart = this.tryToParseAgent(message.slice(i), message, i, new Position(lineNumber, column), parts);
 				} else if (char === '/') {
 					// TODO try to make this sync
-					newPart = await this.tryToParseSlashCommand(sessionId, message.slice(i), i, new Position(lineNumber, column), parts);
+					newPart = await this.tryToParseSlashCommand(sessionId, message.slice(i), message, i, new Position(lineNumber, column), parts);
 				} else if (char === '$') {
 					newPart = await this.tryToParseDynamicVariable(sessionId, message.slice(i), i, new Position(lineNumber, column), parts);
 				}
@@ -79,36 +79,13 @@ export class ChatRequestParser {
 				message.slice(lastPartEnd, message.length)));
 		}
 
-
-		// fix up parts:
-		// * only one agent at the beginning of the message
-		// * only one agent command after the agent or at the beginning of the message
-		let agentIndex = -1;
-		for (let i = 0; i < parts.length; i++) {
-			const part = parts[i];
-			if (part instanceof ChatRequestAgentPart) {
-				if (i === 0) {
-					agentIndex = 0;
-				} else {
-					// agent not first -> make text part
-					parts[i] = new ChatRequestTextPart(part.range, part.editorRange, part.text);
-				}
-			}
-			if (part instanceof ChatRequestAgentSubcommandPart) {
-				if (!(i === 0 || agentIndex === 0 && i === 2 && /^\s+$/.test(parts[1].text))) {
-					// agent command not after agent nor first -> make text part
-					parts[i] = new ChatRequestTextPart(part.range, part.editorRange, part.text);
-				}
-			}
-		}
-
 		return {
 			parts,
 			text: message,
 		};
 	}
 
-	private tryToParseAgent(message: string, offset: number, position: IPosition, parts: ReadonlyArray<IParsedChatRequestPart>): ChatRequestAgentPart | ChatRequestVariablePart | undefined {
+	private tryToParseAgent(message: string, fullMessage: string, offset: number, position: IPosition, parts: ReadonlyArray<IParsedChatRequestPart>): ChatRequestAgentPart | ChatRequestVariablePart | undefined {
 		const nextVariableMatch = message.match(agentReg);
 		if (!nextVariableMatch) {
 			return;
@@ -118,17 +95,29 @@ export class ChatRequestParser {
 		const varRange = new OffsetRange(offset, offset + full.length);
 		const varEditorRange = new Range(position.lineNumber, position.column, position.lineNumber, position.column + full.length);
 
-		let agent: IChatAgent | undefined;
-		if ((agent = this.agentService.getAgent(name))) {
-			if (parts.some(p => p instanceof ChatRequestAgentPart)) {
-				// Only one agent allowed
-				return;
-			} else {
-				return new ChatRequestAgentPart(varRange, varEditorRange, agent);
-			}
+		const agent = this.agentService.getAgent(name);
+		if (!agent) {
+			return;
 		}
 
-		return;
+		if (parts.some(p => p instanceof ChatRequestAgentPart)) {
+			// Only one agent allowed
+			return;
+		}
+
+		// The agent must come first
+		if (parts.some(p => (p instanceof ChatRequestTextPart && p.text.trim() !== '') || !(p instanceof ChatRequestAgentPart))) {
+			return;
+		}
+
+		const previousPart = parts.at(-1);
+		const previousPartEnd = previousPart?.range.endExclusive ?? 0;
+		const textSincePreviousPart = fullMessage.slice(previousPartEnd, offset);
+		if (textSincePreviousPart.trim() !== '') {
+			return;
+		}
+
+		return new ChatRequestAgentPart(varRange, varEditorRange, agent);
 	}
 
 	private tryToParseVariable(message: string, offset: number, position: IPosition, parts: ReadonlyArray<IParsedChatRequestPart>): ChatRequestAgentPart | ChatRequestVariablePart | undefined {
@@ -149,8 +138,8 @@ export class ChatRequestParser {
 		return;
 	}
 
-	private async tryToParseSlashCommand(sessionId: string, message: string, offset: number, position: IPosition, parts: ReadonlyArray<IParsedChatRequestPart>): Promise<ChatRequestSlashCommandPart | ChatRequestAgentSubcommandPart | undefined> {
-		const nextSlashMatch = message.match(slashReg);
+	private async tryToParseSlashCommand(sessionId: string, remainingMessage: string, fullMessage: string, offset: number, position: IPosition, parts: ReadonlyArray<IParsedChatRequestPart>): Promise<ChatRequestSlashCommandPart | ChatRequestAgentSubcommandPart | undefined> {
+		const nextSlashMatch = remainingMessage.match(slashReg);
 		if (!nextSlashMatch) {
 			return;
 		}
@@ -166,6 +155,18 @@ export class ChatRequestParser {
 
 		const usedAgent = parts.find((p): p is ChatRequestAgentPart => p instanceof ChatRequestAgentPart);
 		if (usedAgent) {
+			// The slash command must come immediately after the agent
+			if (parts.some(p => (p instanceof ChatRequestTextPart && p.text.trim() !== '') || !(p instanceof ChatRequestAgentPart) && !(p instanceof ChatRequestTextPart))) {
+				return;
+			}
+
+			const previousPart = parts.at(-1);
+			const previousPartEnd = previousPart?.range.endExclusive ?? 0;
+			const textSincePreviousPart = fullMessage.slice(previousPartEnd, offset);
+			if (textSincePreviousPart.trim() !== '') {
+				return;
+			}
+
 			const subCommands = await usedAgent.agent.provideSlashCommands(CancellationToken.None);
 			const subCommand = subCommands.find(c => c.name === command);
 			if (subCommand) {

src/vs/workbench/contrib/chat/test/common/__snapshots__/ChatRequestParser_agent_and_subcommand_after_newline.0.snap

@@ -0,0 +1,82 @@
+{
+  parts: [
+    {
+      range: {
+        start: 0,
+        endExclusive: 5
+      },
+      editorRange: {
+        startLineNumber: 1,
+        startColumn: 1,
+        endLineNumber: 2,
+        endColumn: 1
+      },
+      text: "    \n",
+      kind: "text"
+    },
+    {
+      range: {
+        start: 5,
+        endExclusive: 11
+      },
+      editorRange: {
+        startLineNumber: 2,
+        startColumn: 1,
+        endLineNumber: 2,
+        endColumn: 7
+      },
+      agent: {
+        id: "agent",
+        metadata: { description: "" },
+        provideSlashCommands: [Function provideSlashCommands]
+      },
+      kind: "agent"
+    },
+    {
+      range: {
+        start: 11,
+        endExclusive: 12
+      },
+      editorRange: {
+        startLineNumber: 2,
+        startColumn: 7,
+        endLineNumber: 3,
+        endColumn: 1
+      },
+      text: "\n",
+      kind: "text"
+    },
+    {
+      range: {
+        start: 12,
+        endExclusive: 23
+      },
+      editorRange: {
+        startLineNumber: 3,
+        startColumn: 1,
+        endLineNumber: 3,
+        endColumn: 12
+      },
+      command: {
+        name: "subCommand",
+        description: ""
+      },
+      kind: "subcommand"
+    },
+    {
+      range: {
+        start: 23,
+        endExclusive: 30
+      },
+      editorRange: {
+        startLineNumber: 3,
+        startColumn: 12,
+        endLineNumber: 3,
+        endColumn: 19
+      },
+      text: " Thanks",
+      kind: "text"
+    }
+  ],
+  text: "    \n@agent\n/subCommand Thanks"
+}

src/vs/workbench/contrib/chat/test/common/__snapshots__/ChatRequestParser_agent_and_subcommand_with_leading_whitespace.0.snap

@@ -0,0 +1,82 @@
+{
+  parts: [
+    {
+      range: {
+        start: 0,
+        endExclusive: 10
+      },
+      editorRange: {
+        startLineNumber: 1,
+        startColumn: 1,
+        endLineNumber: 2,
+        endColumn: 5
+      },
+      text: "    \r\n\t   ",
+      kind: "text"
+    },
+    {
+      range: {
+        start: 10,
+        endExclusive: 16
+      },
+      editorRange: {
+        startLineNumber: 2,
+        startColumn: 5,
+        endLineNumber: 2,
+        endColumn: 11
+      },
+      agent: {
+        id: "agent",
+        metadata: { description: "" },
+        provideSlashCommands: [Function provideSlashCommands]
+      },
+      kind: "agent"
+    },
+    {
+      range: {
+        start: 16,
+        endExclusive: 23
+      },
+      editorRange: {
+        startLineNumber: 2,
+        startColumn: 11,
+        endLineNumber: 3,
+        endColumn: 5
+      },
+      text: " \r\n\t   ",
+      kind: "text"
+    },
+    {
+      range: {
+        start: 23,
+        endExclusive: 34
+      },
+      editorRange: {
+        startLineNumber: 3,
+        startColumn: 5,
+        endLineNumber: 3,
+        endColumn: 16
+      },
+      command: {
+        name: "subCommand",
+        description: ""
+      },
+      kind: "subcommand"
+    },
+    {
+      range: {
+        start: 34,
+        endExclusive: 41
+      },
+      editorRange: {
+        startLineNumber: 3,
+        startColumn: 16,
+        endLineNumber: 3,
+        endColumn: 23
+      },
+      text: " Thanks",
+      kind: "text"
+    }
+  ],
+  text: "    \r\n\t   @agent \r\n\t   /subCommand Thanks"
+}