fix: go-reloaded code editor UX — correct starter, stdin visibility, …

app/api/exercises/[id]/session/route.ts

@@ -19,7 +19,7 @@ export async function GET(
   // Check exercise-level start_time BEFORE creating a session
   // This way participants who haven't started yet are blocked at the exercise level
   const exerciseRows = await sql`
-    SELECT start_time, end_time, duration_limit, question_count
+    SELECT slug, start_time, end_time, duration_limit, question_count
     FROM exercises WHERE id = ${exerciseId} LIMIT 1
   `;
   if (exerciseRows.length === 0) {
@@ -117,6 +117,7 @@ export async function GET(
 
   return NextResponse.json({
     session_id: row.id,
+    exercise_slug: exercise.slug as string,
     current_question_index: row.current_question_index as number,
     question_count: row.question_count as number,
     remaining_seconds: remainingSeconds,

app/api/instructor/exercises/[id]/questions/sync/route.ts

@@ -0,0 +1,54 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getServerSession } from 'next-auth';
+import { authOptions } from '@/lib/auth';
+import { sql } from '@/lib/db';
+import { audit } from '@/lib/audit';
+import { loadExercise } from '@/lib/questions';
+
+/**
+ * POST /api/instructor/exercises/:id/questions/sync
+ *
+ * Re-reads the exercise question files from disk and replaces all questions in the DB.
+ * Only works for exercises that have a matching docs/ directory.
+ */
+export async function POST(
+  _req: NextRequest,
+  { params }: { params: { id: string } }
+) {
+  const session = await getServerSession(authOptions);
+  if (!session?.user?.role || session.user.role !== 'instructor') {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const exerciseRows = await sql`SELECT id, slug FROM exercises WHERE id = ${params.id} LIMIT 1`;
+  if (exerciseRows.length === 0) {
+    return NextResponse.json({ error: 'Exercise not found' }, { status: 404 });
+  }
+
+  const slug = exerciseRows[0].slug as string;
+
+  let exercise;
+  try {
+    exercise = loadExercise(slug);
+  } catch (e: unknown) {
+    return NextResponse.json({ error: e instanceof Error ? e.message : 'Failed to load exercise files' }, { status: 422 });
+  }
+
+  await sql`DELETE FROM questions WHERE exercise_id = ${params.id}`;
+
+  for (const q of exercise.questions) {
+    await sql`
+      INSERT INTO questions (exercise_id, question_index, text, type, language, starter)
+      VALUES (${params.id}, ${q.index}, ${q.text}, ${q.type}, ${q.language}, ${q.starter})
+    `;
+  }
+
+  await sql`UPDATE exercises SET question_count = ${exercise.questions.length} WHERE id = ${params.id}`;
+
+  await audit(session.user.id, 'questions.synced', 'exercise', params.id, {
+    slug,
+    count: exercise.questions.length,
+  });
+
+  return NextResponse.json({ synced: exercise.questions.length });
+}

app/api/instructor/exercises/[id]/questions/upload/route.ts

@@ -51,9 +51,13 @@ export async function POST(
 
   const content = await file.text();
 
-  // Detect question type from form field
-  const questionType = (formData.get('type') as string) ?? 'written';
-  const language = (formData.get('language') as string) ?? 'text';
+  const CODE_EXERCISE_SLUGS = new Set(['ascii-art', 'ascii-art-web', 'go-reloaded']);
+  const exerciseSlug = exerciseRows[0].slug as string;
+  const slugDefault = CODE_EXERCISE_SLUGS.has(exerciseSlug) ? { type: 'code', language: 'go' } : { type: 'written', language: 'text' };
+
+  // Detect question type from form field, falling back to slug-based default
+  const questionType = (formData.get('type') as string) || slugDefault.type;
+  const language = (formData.get('language') as string) || slugDefault.language;
 
   const parts = splitMarkdownQuestions(content);
 

app/api/run-code/route.ts

@@ -34,14 +34,14 @@ export async function POST(req: NextRequest) {
     }, { status: 503 });
   }
 
-  let body: { code: string; language: string; stdin?: string };
+  let body: { code: string; language: string; stdin?: string; exercise?: string };
   try {
     body = await req.json();
   } catch {
     return NextResponse.json({ error: 'Invalid JSON' }, { status: 400 });
   }
 
-  const { code, language, stdin = '' } = body;
+  const { code, language, stdin = '', exercise = '' } = body;
 
   if (!code || typeof code !== 'string') {
     return NextResponse.json({ error: 'code is required' }, { status: 400 });
@@ -53,8 +53,9 @@ export async function POST(req: NextRequest) {
     return NextResponse.json({ error: 'Code exceeds 64KB limit' }, { status: 413 });
   }
 
-  // Auto-inject banner as stdin for Go exercises if no stdin provided
-  const effectiveStdin = stdin || (language === 'go' ? getBannerContent() : '');
+  const BANNER_EXERCISE_SLUGS = new Set(['ascii-art', 'ascii-art-web']);
+  // Auto-inject banner as stdin only for banner exercises when no stdin provided
+  const effectiveStdin = stdin || (language === 'go' && BANNER_EXERCISE_SLUGS.has(exercise) ? getBannerContent() : '');
 
   try {
     const res = await fetch(`${RUNNER_URL}/run`, {

app/instructor/exercises/[id]/QuestionManager.tsx

@@ -3,7 +3,7 @@
 import { useState, useRef } from 'react';
 import ReactMarkdown from 'react-markdown';
 import { toast } from 'sonner';
-import { Plus, Trash2, Edit3, ChevronDown, ChevronUp, Save, X, Upload, FileText } from 'lucide-react';
+import { Plus, Trash2, Edit3, ChevronDown, ChevronUp, Save, X, Upload, FileText, RefreshCw } from 'lucide-react';
 
 interface Question {
   id: string;
@@ -14,22 +14,32 @@ interface Question {
   starter: string;
 }
 
+const CODE_EXERCISE_SLUGS = new Set(['ascii-art', 'ascii-art-web', 'go-reloaded']);
+
+function defaultsForSlug(slug: string): { type: string; language: string } {
+  if (CODE_EXERCISE_SLUGS.has(slug)) return { type: 'code', language: 'go' };
+  return { type: 'written', language: 'text' };
+}
+
 interface Props {
   exerciseId: string;
+  exerciseSlug: string;
   initialQuestions: Question[];
 }
 
-export default function QuestionManager({ exerciseId, initialQuestions }: Props) {
+export default function QuestionManager({ exerciseId, exerciseSlug, initialQuestions }: Props) {
+  const defaults = defaultsForSlug(exerciseSlug);
   const [questions, setQuestions] = useState<Question[]>(initialQuestions);
   const [expanded, setExpanded] = useState<string | null>(null);
   const [editing, setEditing] = useState<string | null>(null);
   const [editDraft, setEditDraft] = useState<Partial<Question>>({});
   const [adding, setAdding] = useState(false);
-  const [newQ, setNewQ] = useState({ text: '', type: 'written', language: 'text', starter: '' });
+  const [newQ, setNewQ] = useState({ text: '', type: defaults.type, language: defaults.language, starter: '' });
   const [saving, setSaving] = useState(false);
   const [uploading, setUploading] = useState(false);
-  const [uploadType, setUploadType] = useState('written');
-  const [uploadLang, setUploadLang] = useState('text');
+  const [syncing, setSyncing] = useState(false);
+  const [uploadType, setUploadType] = useState(defaults.type);
+  const [uploadLang, setUploadLang] = useState(defaults.language);
   const [dragOver, setDragOver] = useState(false);
   const fileInputRef = useRef<HTMLInputElement>(null);
 
@@ -60,8 +70,23 @@ export default function QuestionManager({ exerciseId, initialQuestions }: Props)
     }
   }
 
-  function handleDrop(e: React.DragEvent) {
-    e.preventDefault();
+  async function syncFromFiles() {
+    if (!confirm('Sync questions from docs files? This will replace all current questions.')) return;
+    setSyncing(true);
+    try {
+      const res = await fetch(`/api/instructor/exercises/${exerciseId}/questions/sync`, { method: 'POST' });
+      const data = await res.json();
+      if (!res.ok) throw new Error(data.error ?? 'Sync failed');
+      toast.success(`Synced ${data.synced} questions from files`);
+      window.location.reload();
+    } catch (e: unknown) {
+      toast.error(e instanceof Error ? e.message : 'Sync failed');
+    } finally {
+      setSyncing(false);
+    }
+  }
+
+  function handleDrop(e: React.DragEvent) {    e.preventDefault();
     setDragOver(false);
     const file = e.dataTransfer.files?.[0];
     if (!file) return;
@@ -224,7 +249,12 @@ export default function QuestionManager({ exerciseId, initialQuestions }: Props)
       <div className="card">
         <div className="card-header">
           <span className="card-title">Bulk Import from Markdown</span>
-          <span className="badge badge-orange">Replaces all questions</span>
+          <div style={{ display: 'flex', gap: '0.5rem', alignItems: 'center' }}>
+            <button className="btn btn-sm btn-secondary" disabled={syncing} onClick={syncFromFiles} title="Re-read questions from docs/ files and update the database">
+              <RefreshCw size={12} /> {syncing ? 'Syncing…' : 'Sync from files'}
+            </button>
+            <span className="badge badge-orange">Replaces all questions</span>
+          </div>
         </div>
         <p style={{ fontSize: 12, color: 'var(--text3)', marginBottom: '1rem', lineHeight: 1.7 }}>
           Upload a <code style={{ background: 'var(--bg3)', border: '1px solid var(--border)', padding: '1px 5px', borderRadius: 3, color: 'var(--accent2)' }}>.md</code> file

app/instructor/exercises/[id]/page.tsx

@@ -103,6 +103,7 @@ export default async function ExercisePage({ params }: Props) {
             </div>
             <QuestionManager
               exerciseId={id}
+              exerciseSlug={exercise.slug}
               initialQuestions={questionRows as { id: string; question_index: number; text: string; type: 'written' | 'code'; language: string; starter: string }[]}
             />
           </div>

app/participant/session/[id]/CodeEditor.tsx

@@ -97,15 +97,16 @@ interface Props {
   language: string;
   starter: string;
   isClosed: boolean;
+  exerciseSlug: string;
 }
 
-export default function CodeEditor({ sessionId, questionIndex, language, starter, isClosed }: Props) {
+export default function CodeEditor({ sessionId, questionIndex, language, starter, isClosed, exerciseSlug }: Props) {
   const [code, setCode] = useState(starter);
   const [running, setRunning] = useState(false);
   const [result, setResult] = useState<RunResult | null>(null);
   const [saveStatus, setSaveStatus] = useState<'idle' | 'saving' | 'saved' | 'failed'>('idle');
   const [stdin, setStdin] = useState('');
-  const [showStdin, setShowStdin] = useState(false);
+  const [showStdin, setShowStdin] = useState(exerciseSlug === 'go-reloaded');
   const [editorTheme, setEditorTheme] = useState('recoding-dark');
 
   const codeRef = useRef(code);
@@ -142,7 +143,7 @@ export default function CodeEditor({ sessionId, questionIndex, language, starter
         const res = await fetch(`/api/submissions/${sessionId}/restore?q=${questionIndex}`);
         if (!res.ok) return;
         const data = await res.json();
-        if (data.response_text) {
+        if (data.response_text && data.response_text.trim().length > starter.trim().length) {
           setCode(data.response_text);
           lastSavedRef.current = data.response_text;
           prevLengthRef.current = data.response_text.length;
@@ -289,7 +290,7 @@ export default function CodeEditor({ sessionId, questionIndex, language, starter
       const res = await fetch('/api/run-code', {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ code: codeRef.current, language, stdin }),
+        body: JSON.stringify({ code: codeRef.current, language, stdin, exercise: exerciseSlug }),
       });
       const data = await res.json();
       setResult(res.ok ? data as RunResult : { stdout: '', stderr: data.error ?? 'Unknown error', compile_output: '', exit_code: 1 });
@@ -300,7 +301,7 @@ export default function CodeEditor({ sessionId, questionIndex, language, starter
     }
   }
 
-  const hasOutput = result && (result.stdout || result.stderr || result.compile_output);
+  const hasOutput = result !== null;
   const success = result?.exit_code === 0;
 
   return (
@@ -330,7 +331,7 @@ export default function CodeEditor({ sessionId, questionIndex, language, starter
             rows={3}
             value={stdin}
             onChange={(e) => setStdin(e.target.value)}
-            placeholder="Input to pass via stdin…"
+            placeholder={exerciseSlug === 'go-reloaded' ? 'Type your test input here…' : 'Input to pass via stdin…'}
             style={{ minHeight: 'unset', fontFamily: 'monospace', fontSize: 13 }}
           />
         </div>
@@ -379,11 +380,15 @@ export default function CodeEditor({ sessionId, questionIndex, language, starter
               <pre style={{ margin: 0, fontSize: 12, color: '#fca5a5', whiteSpace: 'pre-wrap', wordBreak: 'break-word' }}>{result.compile_output}</pre>
             </div>
           )}
-          {result?.stdout && (
+          {result?.stdout ? (
             <div style={{ padding: '0.75rem', borderBottom: result?.stderr ? '1px solid var(--border)' : undefined }}>
               <div style={{ fontSize: 11, fontWeight: 700, color: 'var(--green)', marginBottom: '0.4rem', textTransform: 'uppercase' }}>stdout</div>
               <pre style={{ margin: 0, fontSize: 12, color: 'var(--text)', whiteSpace: 'pre-wrap', wordBreak: 'break-word', maxHeight: 300, overflowY: 'auto' }}>{result.stdout}</pre>
             </div>
+          ) : !result?.stderr && !result?.compile_output && (
+            <div style={{ padding: '0.75rem' }}>
+              <span style={{ fontSize: 12, color: 'var(--text3)', fontStyle: 'italic' }}>No output — your program ran but printed nothing. Did you forget to provide stdin?</span>
+            </div>
           )}
           {result?.stderr && (
             <div style={{ padding: '0.75rem' }}>

app/participant/session/[id]/SessionView.tsx

@@ -8,7 +8,7 @@ import { AlertTriangle } from 'lucide-react';
 
 interface QuestionStatus { question_index: number; has_draft: boolean; is_final: boolean; }
 interface SessionState {
-  session_id: string; current_question_index: number; question_count: number;
+  session_id: string; exercise_slug: string; current_question_index: number; question_count: number;
   remaining_seconds: number | null; warning_low_time: boolean; question_statuses: QuestionStatus[];
 }
 interface Question {
@@ -226,6 +226,7 @@ export default function SessionView({ exerciseId }: { exerciseId: string }) {
           language={question.language}
           starter={question.starter}
           isClosed={sessionClosed}
+          exerciseSlug={sessionState.exercise_slug}
         />
       ) : (
         <ResponseEditor

docs/go-reloaded/question0.md

@@ -1,10 +1,6 @@
 ## Drill 1 — Read Input Text from Stdin
 
-Write a function that reads the entire input from stdin and returns it as a string:
-
-```go
-func readInput() string
-```
+Write a function `readInput() string` that reads the entire input from stdin and returns it as a string:
 
 **Requirements:**
 - Read all lines from stdin

docs/go-reloaded/question1.md

@@ -1,10 +1,6 @@
 ## Drill 2 — Convert `(hex)` Tags
 
-Write a function that finds every `(hex)` tag and replaces the word immediately before it with its decimal value:
-
-```go
-func convertHex(text string) string
-```
+Write a function `convertHex(text string) string` that finds every `(hex)` tag and replaces the word immediately before it with its decimal value:
 
 **Requirements:**
 - The word before `(hex)` is always a valid hexadecimal number

docs/go-reloaded/question2.md

@@ -1,10 +1,6 @@
 ## Drill 3 — Convert `(bin)` Tags
 
-Write a function that finds every `(bin)` tag and replaces the word immediately before it with its decimal value:
-
-```go
-func convertBin(text string) string
-```
+Write a function `convertBin(text string) string` that finds every `(bin)` tag and replaces the word immediately before it with its decimal value:
 
 **Requirements:**
 - The word before `(bin)` is always a valid binary number

docs/go-reloaded/question3.md

@@ -1,10 +1,6 @@
 ## Drill 4 — Single-Word `(up)`, `(low)`, `(cap)`
 
-Write a function that handles single-word case modifiers:
-
-```go
-func applySingleCaseModifiers(text string) string
-```
+Write a function `applySingleCaseModifiers(text string) string` that handles single-word case modifiers:
 
 **Requirements:**
 - `(up)` → converts the word immediately before it to UPPERCASE

docs/go-reloaded/question4.md

@@ -1,10 +1,6 @@
 ## Drill 5 — Multi-Word `(up, N)`, `(low, N)`, `(cap, N)`
 
-Extend your case modifier to handle the numbered variant:
-
-```go
-func applyCaseModifiers(text string) string
-```
+Extend your case modifier to handle the numbered variant. Write `applyCaseModifiers(text string) string`:
 
 **Requirements:**
 - `(up, 3)` → converts the 3 words before the tag to uppercase

docs/go-reloaded/question5.md

@@ -1,10 +1,6 @@
 ## Drill 6 — Fix Punctuation Spacing
 
-Write a function that corrects spacing around punctuation marks:
-
-```go
-func fixPunctuation(text string) string
-```
+Write a function `fixPunctuation(text string) string` that corrects spacing around punctuation marks:
 
 **Requirements:**
 - Single punctuation marks (`.`, `,`, `!`, `?`, `:`, `;`) must sit directly after the previous word with no space before them

docs/go-reloaded/question6.md

@@ -1,10 +1,6 @@
 ## Drill 7 — Fix Single-Quote Formatting
 
-Write a function that removes spaces between single-quote marks and the words they wrap:
-
-```go
-func fixSingleQuotes(text string) string
-```
+Write a function `fixSingleQuotes(text string) string` that removes spaces between single-quote marks and the words they wrap:
 
 **Requirements:**
 - Find pairs of `'` marks

docs/go-reloaded/question7.md

@@ -1,10 +1,6 @@
 ## Drill 8 — Fix `a` → `an` Article Rule
 
-Write a function that converts `a` to `an` when the next word starts with a vowel or `h`:
-
-```go
-func fixArticles(text string) string
-```
+Write a function `fixArticles(text string) string` that converts `a` to `an` when the next word starts with a vowel or `h`:
 
 **Requirements:**
 - Every standalone `a` or `A` followed by a word starting with `a`, `e`, `i`, `o`, `u`, or `h` (case-insensitive) becomes `an` / `An`