breaking: remove preserve option (#622)

closes #305
closes #312

Turns out the preserve option doesn't actually do anything useful anymore because it's now looking at lang and not type as it was originally. The original issues are already fixed without specifying preserve at all.

docs/preprocessing.md

@@ -71,7 +71,6 @@ The following options can be passed to the preprocessor. None are required:
 | --------------- | ------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `markupTagName` | `"template"` | `string` that sets the name of the tag `svelte-preprocess` looks for markup in custom languages.<br><br>i.e `markup` makes it possible to write your markup between `<markup lang="..."></markup>` tag.                            |
 | `aliases`       | `null`       | A list of tuples `[alias: string, language: string]` that correlates an `alias` to a `language`<br><br>i.e `['cst', 'customLanguage']` means<br>`<... src="./file.cst">`<br>`<... lang="cst">`<br>are treated as `customLanguage`. |
-| `preserve`      | `[]`         | A `string` list of languages/aliases that shouldn't pass through the preprocessor. (i.e `ld+json`)                                                                                                                                 |
 | `sourceMap`     | `false`      | If `true`, `svelte-preprocess` generates sourcemap for every language that supports it.                                                                                                                                            |
 
 ##### Configuring preprocessors

src/autoProcess.ts

@@ -58,7 +58,6 @@ export function sveltePreprocess(
   {
     aliases,
     markupTagName = 'template',
-    preserve = [],
     sourceMap = process?.env?.NODE_ENV === 'development' ?? false,
     ...rest
   } = {} as AutoPreprocessOptions,
@@ -128,10 +127,6 @@ export function sveltePreprocess(
         lang = getLanguageFromAlias(alias);
       }
 
-      if ((lang && preserve.includes(lang)) || preserve.includes(alias)) {
-        return { code: content };
-      }
-
       const transformerOptions = getTransformerOptions(lang, alias);
 
       content = prepareContent({

src/types/index.ts

@@ -68,7 +68,6 @@ export type AutoPreprocessGroup = PreprocessorGroup;
 export type AutoPreprocessOptions = {
   markupTagName?: string;
   aliases?: Array<[string, string]>;
-  preserve?: string[];
   sourceMap?: boolean;
 
   // transformers

test/autoProcess/autoProcess.test.ts

@@ -107,20 +107,14 @@ describe('options', () => {
     expect(preprocessed.toString?.()).toContain('div{}');
   });
 
-  it('should NOT preprocess preserved languages', async () => {
-    const input = `<div></div><script lang="ld+json">{"json":true}</script>`;
-    const opts = sveltePreprocess({
-      preserve: ['ld+json'],
-      aliases: [['ld+json', 'structuredData']],
-      structuredData() {
-        return { code: '', map: '' };
-      },
-    });
+  it('should NOT preprocess unrecognized languages', async () => {
+    const input = `<div></div><script type="ld+json">{"json":true}</script>`;
+    const opts = sveltePreprocess();
 
     const preprocessed = await preprocess(input, opts);
 
     expect(preprocessed.toString?.()).toContain(
-      `<script lang="ld+json">{"json":true}</script>`,
+      `<script type="ld+json">{"json":true}</script>`,
     );
   });