feat: json support

README.md

@@ -134,21 +134,6 @@ await loadModule('./hello.mjs', { from: import.meta.url })
 
 Options are same as `evalModule`.
 
-### `readModule`
-
-Resolve module path and read source contents. (currently only file protocol supported)
-
-```js
-import { resolve, readModule } from 'mlly'
-
-const indexPath = await resolve('./index.mjs', { from: import.meta.url })
-
-// { code: '...", url: '...' }
-console.log(await readModule(indexPath))
-```
-
-Options are same as `resolve`.
-
 ### `transformModule`
 
 - Resolves all relative imports will be resolved
@@ -161,20 +146,8 @@ console.log(transformModule(`console.log(import.meta.url)`), { url: 'test.mjs' }
 
 Options are same as `evalModule`.
 
-### `toDataURL`
-
-Convert code to [`data:`](https://nodejs.org/api/esm.html#esm_data_imports) URL using base64 encoding.
-
-```js
-import { toDataURL } from 'mlly'
-
-console.log(toDataURL(`
-  // This is an example
-  console.log('Hello world')
-`))
-```
 
-## Other utils
+## Other Utils
 
 ### `fileURLToPath`
 
@@ -201,6 +174,30 @@ import { ensureProtocol } from 'mlly'
 console.log(normalizeid('/foo/bar.js'))
 ```
 
+### `loadURL`
+
+Read source contents of a URL. (currently only file protocol supported)
+
+```js
+import { resolve, loadURL } from 'mlly'
+
+const url = await resolve('./index.mjs', { from: import.meta.url })
+console.log(await loadURL(url))
+```
+
+### `toDataURL`
+
+Convert code to [`data:`](https://nodejs.org/api/esm.html#esm_data_imports) URL using base64 encoding.
+
+```js
+import { toDataURL } from 'mlly'
+
+console.log(toDataURL(`
+  // This is an example
+  console.log('Hello world')
+`))
+```
+
 ## License
 
 MIT

lib/index.d.ts

@@ -28,13 +28,13 @@ export interface EvaluateOptions extends ResolveOptions {
   url?: string
 }
 
-export function loadModule (id: string, opts?: EvaluateOptions) : Promise<any>
+export function loadModule (url: string, opts?: EvaluateOptions) : Promise<any>
 export function evalModule (code: string, opts?: EvaluateOptions) : Promise<any>
-export function readModule (id: string, opts?: EvaluateOptions) : Promise<{ url: string, code: string}>
 export function transformModule(code: string, opts?: EvaluateOptions) : Promise<string>
-export function toDataURL(code: string) : string
 
 // Utils
 
 export function fileURLToPath (id: URL | string) : string
 export function normalizeid (id: URL | string) : string
+export function loadURL (id: string) : Promise<string>
+export function toDataURL(code: string) : string

lib/index.mjs

@@ -112,30 +112,20 @@ export function createResolve (defaults) {
 const ESM_IMPORT_RE = /(?<=import .* from ['"])([^'"]+)(?=['"])|(?<=export .* from ['"])([^'"]+)(?=['"])|(?<=import\s*['"])([^'"]+)(?=['"])|(?<=import\s*\(['"])([^'"]+)(?=['"]\))/g
 
 export async function loadModule (id, opts = {}) {
-  const { url, code } = await readModule(id, opts)
-  return evalModule(code, {
-    url,
-    ...opts
-  })
+  const url = await resolve(id, opts)
+  const code = await loadURL(url, opts)
+  return evalModule(code, { url, ...opts })
 }
 
 export async function evalModule (code, opts = {}) {
   const transformed = await transformModule(code, opts)
   return import(toDataURL(transformed, opts))
 }
 
-export async function readModule (id, opts) {
-  const url = await resolve(id, opts)
-  const code = await fsp.readFile(fileURLToPath(url), 'utf-8')
-  return { url, code }
-}
-
 export async function transformModule (code, opts) {
-  // Use url <> from as defaults of each other
-  if (!opts.url && opts.from) {
-    opts.url = opts.from
-  } else if (opts.url && !opts.from) {
-    opts.from = opts.url
+  // Convert JSON to module
+  if (opts.url && opts.url.endsWith('.json')) {
+    return 'export default ' + code
   }
 
   // Resolve relative imports
@@ -149,11 +139,6 @@ export async function transformModule (code, opts) {
   return code
 }
 
-export function toDataURL (code) {
-  const base64 = Buffer.from(code).toString('base64')
-  return `data:text/javascript;base64,${base64}`
-}
-
 export async function resolveImports (code, opts) {
   const imports = Array.from(code.matchAll(ESM_IMPORT_RE)).map(m => m[0])
   if (!imports.length) {
@@ -162,8 +147,15 @@ export async function resolveImports (code, opts) {
 
   const uniqueImports = Array.from(new Set(imports))
   const resolved = new Map()
-  const resolveOpts = { ...opts, from: opts.url }
-  await Promise.all(uniqueImports.map(async (id) => { resolved.set(id, await resolve(id, resolveOpts)) }))
+  const resolveOpts = { from: opts.from || opts.url, ...opts }
+  await Promise.all(uniqueImports.map(async (id) => {
+    let url = await resolve(id, resolveOpts)
+    if (url.endsWith('.json')) {
+      const code = await loadURL(url)
+      url = toDataURL(await transformModule(code, { url }))
+    }
+    resolved.set(id, url)
+  }))
 
   const re = new RegExp(uniqueImports.map(i => `(${i})`).join('|'), 'g')
   return code.replace(re, id => resolved.get(id))
@@ -191,6 +183,16 @@ export function normalizeid (id) {
   return 'file://' + normalizeSlash(id)
 }
 
+export async function loadURL (url) {
+  const code = await fsp.readFile(fileURLToPath(url), 'utf-8')
+  return code
+}
+
+export function toDataURL (code) {
+  const base64 = Buffer.from(code).toString('base64')
+  return `data:text/javascript;base64,${base64}`
+}
+
 function normalizeSlash (str) {
   return str.replace(/\\/g, '/')
 }

test/eval.mjs

@@ -10,3 +10,5 @@ await evalModule(`
 })
 
 await loadModule('./hello.mjs', { from: import.meta.url })
+
+console.log(await loadModule('../package.json', { from: import.meta.url }).then(r => r.default.name))

test/hello.mjs

@@ -1 +1,3 @@
-console.log('Hello world from', import.meta.url)
+import pkg from '../package.json'
+
+console.log('Hello world from', pkg.name, import.meta.url)