fix(amazonq): Let Enter invoke auto completion more consistently (aws#7700)

## Problem

The VS Code provideInlineCompletionCallback may not trigger when Enter
is pressed, especially in Python files


## Solution
manually make this trigger. In case of duplicate, the
provideInlineCompletionCallback is already debounced

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: leigaol

packages/amazonq/.changes/next-release/Bug Fix-316fb610-0ea9-40d1-bdb7-d371a6be4a4e.json

@@ -0,0 +1,4 @@
+{
+	"type": "Bug Fix",
+	"description": "Let Enter invoke auto completion more consistently"
+}

packages/amazonq/src/app/inline/completion.ts

@@ -241,6 +241,12 @@ export class AmazonQInlineCompletionItemProvider implements InlineCompletionItem
             return []
         }
 
+        const isAutoTrigger = context.triggerKind === InlineCompletionTriggerKind.Automatic
+        if (isAutoTrigger && !CodeSuggestionsState.instance.isSuggestionsEnabled()) {
+            // return early when suggestions are disabled with auto trigger
+            return []
+        }
+
         // yield event loop to let the document listen catch updates
         await sleep(1)
         // prevent user deletion invoking auto trigger
@@ -254,12 +260,6 @@ export class AmazonQInlineCompletionItemProvider implements InlineCompletionItem
         try {
             const t0 = performance.now()
             vsCodeState.isRecommendationsActive = true
-            const isAutoTrigger = context.triggerKind === InlineCompletionTriggerKind.Automatic
-            if (isAutoTrigger && !CodeSuggestionsState.instance.isSuggestionsEnabled()) {
-                // return early when suggestions are disabled with auto trigger
-                return []
-            }
-
             // handling previous session
             const prevSession = this.sessionManager.getActiveSession()
             const prevSessionId = prevSession?.sessionId

packages/amazonq/src/app/inline/documentEventListener.ts

@@ -21,6 +21,11 @@ export class DocumentEventListener {
                     this.lastDocumentChangeEventMap.clear()
                 }
                 this.lastDocumentChangeEventMap.set(e.document.uri.fsPath, { event: e, timestamp: performance.now() })
+                // The VS Code provideInlineCompletionCallback may not trigger when Enter is pressed, especially in Python files
+                // manually make this trigger. In case of duplicate, the provideInlineCompletionCallback is already debounced
+                if (this.isEnter(e) && vscode.window.activeTextEditor) {
+                    void vscode.commands.executeCommand('editor.action.inlineSuggest.trigger')
+                }
             }
         })
     }
@@ -47,4 +52,18 @@ export class DocumentEventListener {
             this.documentChangeListener.dispose()
         }
     }
+
+    private isEnter(e: vscode.TextDocumentChangeEvent): boolean {
+        if (e.contentChanges.length !== 1) {
+            return false
+        }
+        const str = e.contentChanges[0].text
+        if (str.length === 0) {
+            return false
+        }
+        return (
+            (str.startsWith('\r\n') && str.substring(2).trim() === '') ||
+            (str[0] === '\n' && str.substring(1).trim() === '')
+        )
+    }
 }