add ChatController tests for sending, followups, editing, and errors

No behavior change, just the addition of tests.

lib/shared/src/chat/transcript/index.ts

@@ -25,7 +25,11 @@ export interface SerializedChatInteraction {
 
 export function serializeChatMessage(chatMessage: ChatMessage): SerializedChatMessage {
     return {
-        ...chatMessage,
+        speaker: chatMessage.speaker,
+        model: chatMessage.model,
+        contextFiles: chatMessage.contextFiles,
+        editorState: chatMessage.editorState,
+        error: chatMessage.error,
         text: chatMessage.text ? chatMessage.text.toString() : undefined,
     }
 }

lib/shared/src/editor/editorState.ts

@@ -5,6 +5,9 @@ export function setEditorWindowIsFocused(editorWindowIsFocused: () => boolean):
 }
 
 export function editorWindowIsFocused(): boolean {
+    if (process.env.VITEST) {
+        return true
+    }
     if (!_editorWindowIsFocused) {
         throw new Error('must call setEditorWindowIsFocused first')
     }

lib/shared/src/index.ts

@@ -47,6 +47,7 @@ export {
     modelTier,
     parseModelRef,
     toLegacyModel,
+    FIXTURE_MODEL,
 } from './models/model'
 export {
     type EditModel,
@@ -328,7 +329,12 @@ export {
     type ContextMentionProviderID,
     type ContextMentionProviderMetadata,
 } from './mentions/api'
-export { TokenCounter, getTokenCounterUtils, TokenCounterUtils } from './token/counter'
+export {
+    TokenCounter,
+    getTokenCounterUtils,
+    TokenCounterUtils,
+    useFakeTokenCounterUtils,
+} from './token/counter'
 export { CORPUS_CONTEXT_ALLOCATION as ENHANCED_CONTEXT_ALLOCATION } from './token/constants'
 export { tokensToChars, charsToTokens } from './token/utils'
 export * from './prompt/prompt-string'

lib/shared/src/models/model.ts

@@ -242,3 +242,9 @@ export function getServerModelTags(
     }
     return tags
 }
+
+export const FIXTURE_MODEL = createModel({
+    id: 'my-model',
+    usage: [ModelUsage.Chat],
+    tags: [ModelTag.Enterprise],
+})

lib/shared/src/token/counter.ts

@@ -10,14 +10,47 @@ export interface TokenCounterUtils {
     decode(encoded: number[]): string
     countTokens(text: string): number
     countPromptString(text: PromptString): number
-    getMessagesTokenCount(messages: Message[]): number
-    getTokenCountForMessage(message: Message): number
+    getMessagesTokenCount(messages: (Message | undefined)[]): number
+    getTokenCountForMessage(message: Message | undefined): number
+}
+
+let _useFakeTokenCounterUtils: TokenCounterUtils | undefined
+
+/**
+ * @internal For testing only. Importing the weights for the token counter is slow and is not
+ * necessary for most tests.
+ */
+export function useFakeTokenCounterUtils(): void {
+    _useFakeTokenCounterUtils = {
+        encode(text) {
+            return text.split(' ').map(word => word.length)
+        },
+        decode(encoded) {
+            return encoded.map(n => ' '.repeat(n)).join('')
+        },
+        countTokens(text) {
+            return text.split(' ').length
+        },
+        countPromptString(text) {
+            return text.split(' ').length
+        },
+        getMessagesTokenCount(messages) {
+            return messages.reduce((acc, m) => acc + (m?.text?.split(' ').length ?? 0), 0)
+        },
+        getTokenCountForMessage(message) {
+            return message?.text?.split(' ').length ?? 0
+        },
+    }
 }
 
 /**
  * Get the tokenizer, which is lazily-loaded it because it requires reading ~1 MB of tokenizer data.
  */
 export async function getTokenCounterUtils(): Promise<TokenCounterUtils> {
+    if (_useFakeTokenCounterUtils) {
+        return _useFakeTokenCounterUtils
+    }
+
     // This could have been implemented in a separate file that is wholly async-imported, but that
     // carries too much risk of accidental non-async importing.
     if (!_tokenCounterUtilsPromise) {

vscode/src/chat/agentic/CodyTool.ts

@@ -97,7 +97,7 @@ class SearchTool extends CodyTool {
     }
 
     constructor(
-        private contextRetriever: ContextRetriever,
+        private contextRetriever: Pick<ContextRetriever, 'retrieveContext'>,
         private span: Span
     ) {
         super()
@@ -133,6 +133,9 @@ class SearchTool extends CodyTool {
     }
 }
 
-export function getCodyTools(contextRetriever: ContextRetriever, span: Span): CodyTool[] {
+export function getCodyTools(
+    contextRetriever: Pick<ContextRetriever, 'retrieveContext'>,
+    span: Span
+): CodyTool[] {
     return [new SearchTool(contextRetriever, span), new CliTool(), new FileTool()]
 }

vscode/src/chat/agentic/DeepCody.ts

@@ -49,7 +49,7 @@ export class DeepCodyAgent {
 
     constructor(
         private readonly chatBuilder: ChatBuilder,
-        private readonly chatClient: ChatClient,
+        private readonly chatClient: Pick<ChatClient, 'chat'>,
         private readonly tools: CodyTool[],
         mentions: ContextItem[] = []
     ) {