feat: add Vue support (#66)

Co-authored-by: Colby McHenry <me@colbymchenry.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

__tests__/extraction.test.ts

@@ -3080,6 +3080,156 @@ describe('Directory Exclusion', () => {
   });
 });
 
+describe('Vue Extraction', () => {
+  it('should detect Vue files', () => {
+    expect(detectLanguage('App.vue')).toBe('vue');
+    expect(detectLanguage('components/Button.vue')).toBe('vue');
+    expect(isLanguageSupported('vue')).toBe(true);
+  });
+
+  it('should extract component node from a Vue SFC', () => {
+    const code = `<template>
+  <div>{{ message }}</div>
+</template>
+
+<script>
+export default {
+  data() {
+    return { message: 'Hello' };
+  }
+}
+</script>
+`;
+    const result = extractFromSource('HelloWorld.vue', code);
+
+    const componentNode = result.nodes.find((n) => n.kind === 'component');
+    expect(componentNode).toBeDefined();
+    expect(componentNode?.name).toBe('HelloWorld');
+    expect(componentNode?.language).toBe('vue');
+    expect(componentNode?.isExported).toBe(true);
+  });
+
+  it('should extract functions from <script> block', () => {
+    const code = `<template>
+  <button @click="handleClick">Click</button>
+</template>
+
+<script>
+function handleClick() {
+  console.log('clicked');
+}
+
+const count = 0;
+</script>
+`;
+    const result = extractFromSource('Button.vue', code);
+
+    const componentNode = result.nodes.find((n) => n.kind === 'component');
+    expect(componentNode).toBeDefined();
+    expect(componentNode?.name).toBe('Button');
+
+    const funcNode = result.nodes.find((n) => n.kind === 'function' && n.name === 'handleClick');
+    expect(funcNode).toBeDefined();
+    expect(funcNode?.language).toBe('vue');
+  });
+
+  it('should extract from <script setup lang="ts"> block', () => {
+    const code = `<template>
+  <div>{{ count }}</div>
+</template>
+
+<script setup lang="ts">
+import { ref } from 'vue';
+
+const count = ref(0);
+
+function increment(): void {
+  count.value++;
+}
+</script>
+`;
+    const result = extractFromSource('Counter.vue', code);
+
+    const componentNode = result.nodes.find((n) => n.kind === 'component');
+    expect(componentNode).toBeDefined();
+    expect(componentNode?.name).toBe('Counter');
+
+    const funcNode = result.nodes.find((n) => n.kind === 'function' && n.name === 'increment');
+    expect(funcNode).toBeDefined();
+    expect(funcNode?.language).toBe('vue');
+
+    // All nodes should be marked as vue language
+    for (const node of result.nodes) {
+      expect(node.language).toBe('vue');
+    }
+  });
+
+  it('should extract from both <script> and <script setup> blocks', () => {
+    const code = `<template>
+  <div>{{ msg }}</div>
+</template>
+
+<script>
+export default {
+  name: 'DualScript'
+}
+</script>
+
+<script setup>
+const msg = 'hello';
+
+function greet() {
+  return msg;
+}
+</script>
+`;
+    const result = extractFromSource('DualScript.vue', code);
+
+    const componentNode = result.nodes.find((n) => n.kind === 'component');
+    expect(componentNode).toBeDefined();
+
+    const greetFunc = result.nodes.find((n) => n.kind === 'function' && n.name === 'greet');
+    expect(greetFunc).toBeDefined();
+  });
+
+  it('should create component node for template-only Vue file', () => {
+    const code = `<template>
+  <div>Static content</div>
+</template>
+`;
+    const result = extractFromSource('Static.vue', code);
+
+    const componentNode = result.nodes.find((n) => n.kind === 'component');
+    expect(componentNode).toBeDefined();
+    expect(componentNode?.name).toBe('Static');
+    expect(componentNode?.language).toBe('vue');
+
+    // Only the component node should exist (no script nodes)
+    expect(result.nodes.length).toBe(1);
+  });
+
+  it('should create containment edges from component to script nodes', () => {
+    const code = `<template>
+  <div>{{ value }}</div>
+</template>
+
+<script setup lang="ts">
+const value = 42;
+</script>
+`;
+    const result = extractFromSource('Contained.vue', code);
+
+    const componentNode = result.nodes.find((n) => n.kind === 'component');
+    expect(componentNode).toBeDefined();
+
+    // Should have containment edges from component to child nodes
+    const containEdges = result.edges.filter(
+      (e) => e.source === componentNode!.id && e.kind === 'contains'
+    );
+    expect(containEdges.length).toBeGreaterThan(0);
+  });
+});
+
 describe('Instantiates + Decorates edge extraction', () => {
   it('emits an instantiates ref for `new Foo()`', () => {
     const code = `