Robert Jackson
62ed3c25c7
When authoring tooling that parses Handlebars files and emits Handlebars
files, you often want to preserve the **exact** formatting of the input.
The changes in this commit add a new method to the `Handlebars`
namespace: `parseWithoutProcessing`. Unlike, `Handlebars.parse` (which
will mutate the parsed AST to apply whitespace control) this method will
parse the template and return it directly (**without** processing
😉).
For example, parsing the following template:
```hbs
{{#foo}}
{{~bar~}} {{baz~}}
{{/foo}}
```
Using `Handlebars.parse`, the AST returned would have truncated the
following whitespace:
* The whitespace prior to the `{{#foo}}`
* The newline following `{{#foo}}`
* The leading whitespace before `{{~bar~}}`
* The whitespace between `{{~bar~}}` and `{{baz~}}`
* The newline after `{{baz~}}`
* The whitespace prior to the `{{/foo}}`
When `Handlebars.parse` is used from `Handlebars.precompile` or
`Handlebars.compile`, this whitespace stripping is **very** important
(these behaviors are intentional, and generally lead to better rendered
output).
When the same template is parsed with
`Handlebars.parseWithoutProcessing` none of those modifications to the
AST are made. This enables "codemod tooling" (e.g. `prettier` and
`ember-template-recast`) to preserve the **exact** initial formatting.
Prior to these changes, those tools would have to _manually_ reconstruct
the whitespace that is lost prior to emitting source.
33 lines
815 B
JavaScript
33 lines
815 B
JavaScript
import parser from './parser';
|
|
import WhitespaceControl from './whitespace-control';
|
|
import * as Helpers from './helpers';
|
|
import { extend } from '../utils';
|
|
|
|
export { parser };
|
|
|
|
let yy = {};
|
|
extend(yy, Helpers);
|
|
|
|
export function parseWithoutProcessing(input, options) {
|
|
// Just return if an already-compiled AST was passed in.
|
|
if (input.type === 'Program') { return input; }
|
|
|
|
parser.yy = yy;
|
|
|
|
// Altering the shared object here, but this is ok as parser is a sync operation
|
|
yy.locInfo = function(locInfo) {
|
|
return new yy.SourceLocation(options && options.srcName, locInfo);
|
|
};
|
|
|
|
let ast = parser.parse(input);
|
|
|
|
return ast;
|
|
}
|
|
|
|
export function parse(input, options) {
|
|
let ast = parseWithoutProcessing(input, options);
|
|
let strip = new WhitespaceControl(options);
|
|
|
|
return strip.accept(ast);
|
|
}
|