feat: Phase 3 question & routing

- parseQuestionConfig for extracting question blocks
- routeFromQuestion for routing based on user response
- shouldLoopStep for max-iter safety
- getNextStepIndex for combined routing logic
- Handle No* (editable) responses

Author: apiad

.experiments/literate-commands/routing.test.ts

@@ -0,0 +1,173 @@
+/**
+ * Question & Routing tests
+ */
+
+import { describe, test, expect } from 'bun:test';
+import { 
+  parseLiterateMarkdown, 
+  parseQuestionConfig,
+  routeFromQuestion,
+  shouldLoopStep,
+  type Step
+} from './literate-commands';
+
+// ============================================================================
+// Test Data
+// ============================================================================
+
+const QUESTION_STEP = `---
+\`\`\`yaml {config}
+step: approval
+question:
+    title: Do you approve the plan?
+    options:
+        Yes: collect
+        No*: refine
+\`\`\`
+Please approve or refine.
+`;
+
+const LOOP_STEP = `---
+\`\`\`yaml {config}
+step: refine
+next: approval
+max-iter: 3
+\`\`\`
+Refine the plan based on feedback.
+`;
+
+const LINEAR_STEP = `---
+\`\`\`yaml {config}
+step: step1
+next: step2
+\`\`\`
+Do step 1.
+`;
+
+const LINEAR_STEP_2 = `---
+\`\`\`yaml {config}
+step: step2
+\`\`\`
+Do step 2.
+`;
+
+// ============================================================================
+// Tests
+// ============================================================================
+
+describe('parseQuestionConfig', () => {
+  test('extracts question config from step', () => {
+    const steps = parseLiterateMarkdown(QUESTION_STEP);
+    const step = steps[0];
+    
+    const config = parseQuestionConfig(step.config);
+    
+    expect(config).toBeDefined();
+    expect(config?.title).toBe('Do you approve the plan?');
+    expect(config?.options).toEqual({
+      'Yes': 'collect',
+      'No*': 'refine'
+    });
+  });
+
+  test('returns null for steps without question', () => {
+    const steps = parseLiterateMarkdown(LINEAR_STEP);
+    const step = steps[0];
+    
+    const config = parseQuestionConfig(step.config);
+    
+    expect(config).toBeNull();
+  });
+});
+
+describe('routeFromQuestion', () => {
+  test('routes based on Yes response', () => {
+    const steps = parseLiterateMarkdown(QUESTION_STEP);
+    const step = steps[0];
+    
+    const nextStep = routeFromQuestion(step.config, 'Yes');
+    
+    expect(nextStep).toBe('collect');
+  });
+
+  test('routes based on No response', () => {
+    const steps = parseLiterateMarkdown(QUESTION_STEP);
+    const step = steps[0];
+    
+    const nextStep = routeFromQuestion(step.config, 'No');
+    
+    expect(nextStep).toBe('refine');
+  });
+
+  test('returns null for unknown response', () => {
+    const steps = parseLiterateMarkdown(QUESTION_STEP);
+    const step = steps[0];
+    
+    const nextStep = routeFromQuestion(step.config, 'Maybe');
+    
+    expect(nextStep).toBeNull();
+  });
+});
+
+describe('shouldLoopStep', () => {
+  test('returns false for steps without max-iter', () => {
+    const steps = parseLiterateMarkdown(QUESTION_STEP);
+    const step = steps[0];
+    
+    const result = shouldLoopStep(step.config, 0);
+    
+    expect(result).toBe(false);
+  });
+
+  test('returns false when max-iter exceeded', () => {
+    const steps = parseLiterateMarkdown(LOOP_STEP);
+    const step = steps[0];
+    
+    // At iteration 3, should not loop (max is 3)
+    const result = shouldLoopStep(step.config, 3);
+    
+    expect(result).toBe(false);
+  });
+
+  test('returns true when under max-iter', () => {
+    const steps = parseLiterateMarkdown(LOOP_STEP);
+    const step = steps[0];
+    
+    // At iteration 2, should loop
+    const result = shouldLoopStep(step.config, 2);
+    
+    expect(result).toBe(true);
+  });
+});
+
+describe('routing flow', () => {
+  test('linear routing via next:', () => {
+    const steps = parseLiterateMarkdown(LINEAR_STEP);
+    const step1 = steps[0];
+    
+    expect(step1.config.next).toBe('step2');
+  });
+
+  test('routing integration - approval loop', () => {
+    // Simulate approval → No → refine → approval → Yes → collect
+    const approvalStep = { config: { 
+      step: 'approval', 
+      question: { 
+        title: 'Approve?', 
+        options: { 'Yes': 'collect', 'No*': 'refine' } 
+      } 
+    }};
+    
+    // User says No
+    let next = routeFromQuestion(approvalStep.config, 'No');
+    expect(next).toBe('refine');
+    
+    // After refine, next is approval (loop)
+    const refineStep = { config: { step: 'refine', next: 'approval', maxIter: 3 }};
+    expect(refineStep.config.next).toBe('approval');
+    
+    // Loop check
+    expect(shouldLoopStep(refineStep.config, 0)).toBe(true);
+    expect(shouldLoopStep(refineStep.config, 3)).toBe(false); // Max reached
+  });
+});