From c253454db6e56f693e5f5947433115103844ce7e Mon Sep 17 00:00:00 2001
From: Gianluca Guarini <gianluca.guarini@gmail.com>
Date: Fri, 29 Nov 2024 22:43:27 +0100
Subject: [PATCH] closes #178

---
 src/index.js                    | 17 ++++------------
 src/utils/pre-process-source.js | 36 +++++++++++++++++++++++++++++++++
 test/core.spec.js               | 21 ++++++++++++++++++-
 3 files changed, 60 insertions(+), 14 deletions(-)
 create mode 100644 src/utils/pre-process-source.js

diff --git a/src/index.js b/src/index.js
index c604cb1..248ee24 100644
--- a/src/index.js
+++ b/src/index.js
@@ -24,13 +24,13 @@ import { createSlotsArray } from './generators/template/bindings/tag.js'
 import cssGenerator from './generators/css/index.js'
 import curry from 'curri'
 import generateJavascript from './utils/generate-javascript.js'
-import hasHTMLOutsideRootNode from './utils/has-html-outside-root-node.js'
 import isEmptyArray from './utils/is-empty-array.js'
 import isEmptySourcemap from './utils/is-empty-sourcemap.js'
 import javascriptGenerator from './generators/javascript/index.js'
 import riotParser from '@riotjs/parser'
 import sourcemapAsJSON from './utils/sourcemap-as-json.js'
 import templateGenerator from './generators/template/index.js'
+import preProcessSource from './utils/pre-process-source.js'
 
 const DEFAULT_OPTIONS = {
   template: 'default',
@@ -156,26 +156,17 @@ export function generateTemplateFunctionFromString(source, parserOptions) {
 
 /**
  * Generate the output code source together with the sourcemap
- * @param { string } source - source code of the tag we will need to compile
+ * @param { string | ParserResult } source - source code of the tag we will need to compile or a parsed Component AST
  * @param { Object } opts - compiling options
  * @returns { Output } object containing output code and source map
  */
 export function compile(source, opts = {}) {
   const meta = createMeta(source, opts)
   const { options } = meta
-  const { code, map } = runPreprocessor(
-    'template',
-    options.template,
-    meta,
+  const { template, css, javascript, map, code } = preProcessSource(
     source,
+    meta,
   )
-  const { parse } = riotParser(options)
-  const { template, css, javascript } = parse(code).output
-
-  // see also https://github.com/riot/compiler/issues/130
-  if (hasHTMLOutsideRootNode(template || css || javascript, code, parse)) {
-    throw new Error('Multiple HTML root nodes are not supported')
-  }
 
   // extend the meta object with the result of the parsing
   Object.assign(meta, {
diff --git a/src/utils/pre-process-source.js b/src/utils/pre-process-source.js
new file mode 100644
index 0000000..2bbe36a
--- /dev/null
+++ b/src/utils/pre-process-source.js
@@ -0,0 +1,36 @@
+import { isObject } from '@riotjs/util'
+import riotParser from '@riotjs/parser'
+import hasHTMLOutsideRootNode from './has-html-outside-root-node.js'
+import { execute as runPreprocessor } from '../preprocessors.js'
+
+/**
+ * Get an object containing the template, css and javascript ast. The origianl source code and the sourcemap are also included
+ *
+ * @param { string | ParserResult.Output } source - source code of the tag we will need to compile or a parsed Component AST
+ * @param { Object } meta - compiler meta object that will be used to store the meta information of the input across the whole compilation
+ * @returns { Object } object that will be used to generate the output code
+ */
+export default function preProcessSource(source, meta) {
+  // if the source is a parser output we can return it directly
+  // @link https://github.com/riot/compiler/issues/178
+  if (isObject(source)) return { ...source, code: '', map: null }
+
+  const { options } = meta
+
+  const { code, map } = runPreprocessor(
+    'template',
+    options.template,
+    meta,
+    source,
+  )
+
+  const parse = riotParser(options).parse
+  const { template, css, javascript } = parse(code).output
+
+  // see also https://github.com/riot/compiler/issues/130
+  if (hasHTMLOutsideRootNode(template || css || javascript, source, parse)) {
+    throw new Error('Multiple HTML root nodes are not supported')
+  }
+
+  return { template, css, javascript, map, code }
+}
diff --git a/test/core.spec.js b/test/core.spec.js
index 011bc83..8e771cd 100644
--- a/test/core.spec.js
+++ b/test/core.spec.js
@@ -9,6 +9,7 @@ import { evaluateScript, getFixture, sassPreprocessor } from './helpers.js'
 import { SourceMapConsumer } from 'source-map'
 import { expect } from 'chai'
 import pug from 'pug'
+import riotParser from '@riotjs/parser'
 import { unregister } from '../src/preprocessors.js'
 
 describe('Core specs', () => {
@@ -33,12 +34,30 @@ describe('Core specs', () => {
       sourcemapConsumer.destroy()
     })
 
-    it('TypeScript script syntax are supported', function () {
+    it('TypeScript script syntax is supported', function () {
       expect(() =>
         compile(getFixture('typescript-script-type.riot')),
       ).to.not.throw()
     })
 
+    it('The compiler accepts also parsed components AST', async function () {
+      const { parse } = riotParser()
+      const parserResult = parse(getFixture('my-component.riot'))
+      const result = compile(parserResult.output)
+      const output = evaluateScript(result.code)
+
+      expect(result.code).to.be.a('string')
+      expect(result.map).to.be.not.an('undefined')
+      expect(result.meta).to.be.an('object')
+      expect(result.meta.tagName).to.be.equal('my-component')
+      expect(output.default).to.have.all.keys(
+        'exports',
+        'css',
+        'template',
+        'name',
+      )
+    })
+
     it('String attributes should not be removed from the root node (https://github.com/riot/riot/issues/2761)', () => {
       const result = compile(getFixture('static-attributes.riot'))