fix: load custom blocks by index

closes #355

Author: znck

Diff for: examples/custom-block/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "custom-block",
+  "version": "0.0.0",
+  "private": true,
+  "scripts": {
+    "build": "rollup -c"
+  },
+  "dependencies": {
+    "rollup": "^2.10.9",
+    "rollup-pluginutils": "^2.8.2",
+    "rollup-plugin-vue": "link:../.."
+  }
+}

Diff for: examples/custom-block/rollup.config.js

@@ -0,0 +1,33 @@
+import VuePlugin from 'rollup-plugin-vue'
+import { createFilter } from 'rollup-pluginutils'
+
+export default [
+  {
+    input: 'src/App.vue',
+    output: {
+      file: 'dist/app.js',
+      format: 'esm',
+      sourcemap: 'inline',
+    },
+    plugins: [VuePlugin({ customBlocks: ['i18n'] }), VueI18N()],
+    external: ['vue'],
+  },
+]
+
+function VueI18N() {
+  const filter = createFilter([/vue&type=i18n/])
+
+  return {
+    transform(code, id) {
+      if (filter(id)) {
+        return {
+          code: `
+          export default function i18n(component) {
+            component.i18n = ${JSON.stringify(JSON.parse(code.trim()))}
+          }`,
+          map: null,
+        }
+      }
+    },
+  }
+}

Diff for: examples/custom-block/src/App.vue

@@ -0,0 +1,17 @@
+<script>
+export default {
+  name: 'App',
+}
+</script>
+
+<template>
+  <h1>{{ $t('say.hello', { name: 'Rahul' }) }}</h1>
+</template>
+
+<i18n lang="json">
+{
+  "say": {
+    "hello": "Hello :name"
+  }
+}
+</i18n>

Diff for: src/index.ts

@@ -112,7 +112,7 @@ export default function PluginVue(userOptions: Partial<Options> = {}): Plugin {
               ? descriptor.script!
               : query.type === 'style'
               ? descriptor.styles[query.index]
-              : query.type === 'custom'
+              : typeof query.index === 'number'
               ? descriptor.customBlocks[query.index]
               : null
 

Diff for: test/core.e2e.ts

@@ -12,6 +12,22 @@ describe('simple', () => {
   })
 })
 
+describe('custom-block', () => {
+  let result!: RollupOutput
+
+  beforeAll(async () => {
+    result = await roll('custom-block')
+  })
+
+  it('should compile <i18n>', () => {
+    expect(result.output[0].code).toEqual(
+      expect.stringContaining(
+        'component.i18n = {"say":{"hello":"Hello :name"}}'
+      )
+    )
+  })
+})
+
 describe('css-modules', () => {
   let result!: RollupOutput