feat: add fromAcornAst method to create stringified object from acorn…

… ast expressions

src/StringifiedObject/index.ts

@@ -7,6 +7,8 @@
  * file that was distributed with this source code.
 */
 
+import { Parser } from 'edge-parser'
+
 /**
  * This class generates a valid object as a string, which is written to the template
  * output. The reason we need a string like object, since we don't want it's
@@ -42,4 +44,43 @@ export class StringifiedObject {
     this.obj = ''
     return obj
   }
+
+  /**
+   * Parses an array of expressions to form an object. Each expression inside the array must
+   * be `ObjectExpression` or an `AssignmentExpression`, otherwise it will be ignored.
+   *
+   * ```js
+   * (title = 'hello')
+   * // returns { title: 'hello' }
+   *
+   * ({ title: 'hello' })
+   * // returns { title: 'hello' }
+   *
+   * ({ title: 'hello' }, username = 'virk')
+   * // returns { title: 'hello', username: 'virk' }
+   * ```
+   */
+  public static fromAcornExpressions (expressions: any[], parser: Parser): string {
+    if (!Array.isArray(expressions)) {
+      throw new Error('"fromAcornExpressions" expects an array of acorn ast expressions')
+    }
+
+    const objectifyString = new this()
+
+    expressions.forEach((arg) => {
+      if (arg.type === 'ObjectExpression') {
+        arg.properties.forEach((prop: any) => {
+          const key = parser.utils.stringify(prop.key)
+          const value = parser.utils.stringify(prop.value)
+          objectifyString.add(key, value)
+        })
+      }
+
+      if (arg.type === 'AssignmentExpression') {
+        objectifyString.add(arg.left.name, parser.utils.stringify(arg.right))
+      }
+    })
+
+    return objectifyString.flush()
+  }
 }

test/stringified-object.spec.ts

@@ -8,9 +8,23 @@
 */
 
 import test from 'japa'
-
+import { Parser } from 'edge-parser'
 import { StringifiedObject } from '../src/StringifiedObject'
 
+/**
+ * Sample loc
+ */
+const LOC = {
+  start: {
+    line: 1,
+    col: 0,
+  },
+  end: {
+    line: 1,
+    col: 0,
+  },
+}
+
 test.group('StringifiedObject', () => {
   test('add string as a key-value pair to object', (assert) => {
     const stringified = new StringifiedObject()
@@ -42,3 +56,83 @@ test.group('StringifiedObject', () => {
     assert.equal(stringified.flush(), '{ username: { [10, 20] } }')
   })
 })
+
+test.group('StringifiedObject | fromAcornAst', () => {
+  test('stringify object expression', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`({ username: 'virk' })`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions([expression], parser)
+    assert.equal(props, `{ username: 'virk' }`)
+  })
+
+  test('parse props with shorthand obj', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`({ username })`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions([expression], parser)
+    assert.equal(props, `{ username: ctx.resolve('username') }`)
+  })
+
+  test('parse props with computed obj', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`({ [username]: username })`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions([expression], parser)
+    assert.equal(props, `{ ctx.resolve('username'): ctx.resolve('username') }`)
+  })
+
+  test('parse props with multiple obj properties', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`({ username: 'virk', age: 22 })`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions([expression], parser)
+
+    assert.equal(props, `{ username: 'virk', age: 22 }`)
+  })
+
+  test('parse props with shorthand and full properties', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`({ username, age: 22 })`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions([expression], parser)
+    assert.equal(props, `{ username: ctx.resolve('username'), age: 22 }`)
+  })
+
+  test('parse props with assignment expression', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`(title = 'Hello')`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions([expression], parser)
+    assert.equal(props, `{ title: 'Hello' }`)
+  })
+
+  test('parse props with more than one assignment expression', (assert) => {
+    const parser = new Parser({}, { filename: 'eval.edge' })
+    const expression = parser.utils.transformAst(
+      parser.utils.generateAST(`(title = 'Hello', body = 'Some content')`, LOC, parser.options.filename),
+      parser.options.filename,
+    )
+
+    const props = StringifiedObject.fromAcornExpressions(expression.expressions, parser)
+    assert.equal(props, `{ title: 'Hello', body: 'Some content' }`)
+  })
+})