ember-source/dist/dev/packages/@ember/template-compiler/lib/plugins/transform-each-track-array.js

A JavaScript framework for creating ambitious web applications

import '../../../debug/index.js';
import { isPath, trackLocals } from './utils.js';
import { assert } from '../../../debug/lib/assert.js';

/**
 @module ember
*/

/**
  A Glimmer2 AST transformation that replaces all instances of

  ```handlebars
  {{#each iterableThing as |key value|}}
  ```

  with

  ```handlebars
  {{#each (-track-array iterableThing) as |key value|}}
  ```

  @private
  @class TransformHasBlockSyntax
*/
function transformEachTrackArray(env) {
  let {
    builders: b
  } = env.syntax;
  let {
    hasLocal,
    visitor
  } = trackLocals(env);
  return {
    name: 'transform-each-track-array',
    visitor: {
      ...visitor,
      BlockStatement(node) {
        if (isPath(node.path) && node.path.original === 'each' && !hasLocal('each')) {
          let firstParam = node.params[0];
          (!(firstParam) && assert('has firstParam', firstParam));
          if (firstParam.type === 'SubExpression' && firstParam.path.type === 'PathExpression' && firstParam.path.original === '-each-in') {
            return;
          }
          node.params[0] = b.sexpr(b.path('-track-array'), [firstParam]);
          return b.block(b.path('each'), node.params, node.hash, node.program, node.inverse, node.loc);
        }
      }
    }
  };
}

export { transformEachTrackArray as default };