feat: generate objects and arrays from raw source

README.md

@@ -22,6 +22,8 @@ pnpm install knitwork
 
 ## Usage
 
+**Generating ESM syntax:**
+
 ```js
 import { genImport, genExport } from 'knitwork'
 
@@ -47,6 +49,23 @@ console.log(genExport('pkg', ['a', 'b']))
 console.log(genExport('pkg', { name: '*foo*', as: 'bar' }))
 ```
 
+**Serializing JS objects:**
+
+```js
+import { genObjectFromRaw, genObjectFromRawEntries, genArrayFromRaw } from 'knitwork'
+
+// { test: () => import("pkg") }
+console.log(genObjectFromRaw({ test: '() => import("pkg")' }))
+
+// { test: () => import("pkg") }
+console.log(genObjectFromRaw([ ['test', '() => import("pkg")'] ]))
+
+console.log(genObjectFromRawEntries(entries))
+
+// [ 1, 2, () => import("pkg") ]
+console.log(genArrayFromRaw(['1', '2', '() => import("pkg")']))
+```
+
 ## 💻 Development
 
 - Clone this repository

src/esm.ts

@@ -1,6 +1,6 @@
 
 import { CodegenOptions } from './types'
-import { genString } from './js'
+import { genString } from './string'
 
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import
 // https://tc39.es/ecma262/multipage/ecmascript-language-scripts-and-modules.html#sec-imports

src/index.ts

@@ -1,3 +1,4 @@
 export * from './esm'
-export * from './js'
+export * from './object'
+export * from './string'
 export * from './types'

src/object.ts

@@ -0,0 +1,47 @@
+import { genString } from './string'
+
+export function genObjectFromRaw (obj: Record<string, any>, indent = ''): string {
+  return genObjectFromRawEntries(Object.entries(obj), indent)
+}
+
+export function genArrayFromRaw (array: any[], indent = '') {
+  const newIdent = indent + '  '
+  return wrapInDelimiters(array.map(i => `${newIdent}${genRawValue(i, newIdent)}`), indent, '[]')
+}
+
+export function genObjectFromRawEntries (array: [key: string, value: any][], indent = '') {
+  const newIdent = indent + '  '
+  return wrapInDelimiters(array.map(([key, value]) => `${newIdent}${genObjectKey(key)}: ${genRawValue(value, newIdent)}`), indent, '{}')
+}
+
+// --- Internals ---
+
+function wrapInDelimiters (lines: string[], indent = '', delimiters = '{}') {
+  if (!lines.length) {
+    return delimiters
+  }
+  const [start, end] = delimiters
+  return `${start}\n` + lines.join(',\n') + `\n${indent}${end}`
+}
+
+function genRawValue (value: unknown, indent = ''): string {
+  if (typeof value === 'undefined') {
+    return 'undefined'
+  }
+  if (value === null) {
+    return 'null'
+  }
+  if (Array.isArray(value)) {
+    return genArrayFromRaw(value, indent)
+  }
+  if (value && typeof value === 'object') {
+    return genObjectFromRaw(value, indent)
+  }
+  return value.toString()
+}
+
+const VALID_IDENTIFIER_RE = /^[$_]?[\w\d]*$/
+
+function genObjectKey (key: string) {
+  return key.match(VALID_IDENTIFIER_RE) ? key : genString(key)
+}

src/string.ts

@@ -0,0 +1,18 @@
+import type { CodegenOptions } from './types'
+
+export function genString (input: string, opts: CodegenOptions = {}) {
+  const str = JSON.stringify(input)
+  if (!opts.singleQuotes) {
+    return JSON.stringify(input)
+  }
+  return `'${escapeString(str)}'`
+}
+
+// https://github.com/rollup/rollup/blob/master/src/utils/escapeId.ts
+const NEEDS_ESCAPE_RE = /[\\'\r\n\u2028\u2029]/
+const QUOTE_NEWLINE_RE = /(['\r\n\u2028\u2029])/g
+const BACKSLASH_RE = /\\/g
+export function escapeString (id: string): string {
+  if (!id.match(NEEDS_ESCAPE_RE)) { return id }
+  return id.replace(BACKSLASH_RE, '\\\\').replace(QUOTE_NEWLINE_RE, '\\$1')
+}

test/index.test.ts

@@ -1,5 +1,5 @@
 import { expect, describe, it } from 'vitest'
-import { genImport, genExport, genDynamicImport } from '../src'
+import { genImport, genExport, genDynamicImport, genObjectFromRaw, genObjectFromRawEntries } from '../src'
 
 const genImportTests = [
   { names: 'foo', code: 'import foo from "pkg";' },
@@ -53,3 +53,58 @@ describe('genDynamicImport', () => {
     })
   }
 })
+
+const genObjectFromRawTests = [
+  {
+    obj: {
+      a: 'null',
+      b: null,
+      c: undefined,
+      1: 'undefined',
+      2: true,
+      3: 'true',
+      'obj 1': '{ literal: () => "test" }',
+      'obj 2': { nested: { foo: '"bar"' } },
+      arr: ['1', '2', '3']
+    },
+    code: [
+      '{',
+      '  1: undefined,',
+      '  2: true,',
+      '  3: true,',
+      '  a: null,',
+      '  b: null,',
+      '  c: undefined,',
+      '  "obj 1": { literal: () => "test" },',
+      '  "obj 2": {',
+      '    nested: {',
+      '      foo: "bar"',
+      '    }',
+      '  },',
+      '  arr: [',
+      '    1,',
+      '    2,',
+      '    3',
+      '  ]',
+      '}'
+    ].join('\n')
+  }
+]
+
+describe('genObjectFromRaw', () => {
+  for (const t of genObjectFromRawTests) {
+    it(t.code, () => {
+      const code = genObjectFromRaw(t.obj)
+      expect(code).to.equal(t.code)
+    })
+  }
+})
+
+describe('genObjectFromRawEntries', () => {
+  for (const t of genObjectFromRawTests) {
+    it(t.code, () => {
+      const code = genObjectFromRawEntries(Object.entries(t.obj))
+      expect(code).to.equal(t.code)
+    })
+  }
+})