Merge pull request #15 from ieedan/formatting

feat: formatting

Author: ieedan

.changeset/six-clocks-battle.md

@@ -0,0 +1,5 @@
+---
+"sv-strip": minor
+---
+
+feat: Remove leading and trailing whitespace from removed nodes.

README.md

@@ -36,10 +36,16 @@ const js = strip(ts);
 <input bind:value/>
 ```
 
-## Limitations
+## Formatting
+
+By default `sv-strip` will remove leading and trailing whitespace when removing nodes. This will result in an output that is correctly formatted (with a small performance penalty).
+
+If you are doing your own formatting you can disable this behavior with the `format` option like so:
+```ts
+const js = strip(ts, { format: false });
+```
 
-### Formatting
-`sv-strip` doesn't format the code so we recommend running the output through a formatter to prevent unnecessary (and ugly) whitespace in your code.
+## Limitations
 
 ### Unsupported Syntax
 

package.json

@@ -14,13 +14,7 @@
 	"bugs": {
 		"url": "https://github.com/ieedan/sv-strip/issues"
 	},
-	"keywords": [
-		"svelte",
-		"strip",
-		"types",
-		"typescript",
-		"javascript"
-	],
+	"keywords": ["svelte", "strip", "types", "typescript", "javascript"],
 	"packageManager": "pnpm@10.4.1",
 	"type": "module",
 	"scripts": {
@@ -32,9 +26,7 @@
 		"changeset": "changeset",
 		"ci:release": "unbuild && changeset publish"
 	},
-	"files": [
-		"dist"
-	],
+	"files": ["dist"],
 	"exports": {
 		".": {
 			"import": "./dist/index.mjs",

src/index.ts

@@ -5,6 +5,8 @@ import { type AST, parse } from 'svelte/compiler';
 export type Options = {
 	/** Used for debugging hints. */
 	filename?: string;
+	/** Should the output be formatted. (Turn this off if you are doing your own formatting) @default true */
+	format?: boolean;
 };
 
 /** Strips the types from the provided Svelte source.
@@ -35,8 +37,11 @@ export type Options = {
  * assert(stripped === expected);
  * ```
  */
-export function strip(source: string, options?: Options): string {
-	const ast = parse(source, { filename: options?.filename });
+export function strip(
+	source: string,
+	{ filename = undefined, format = true }: Options = {}
+): string {
+	const ast = parse(source, { filename });
 
 	const src = new MagicString(source);
 
@@ -61,8 +66,14 @@ export function strip(source: string, options?: Options): string {
 			'TSInterfaceDeclaration',
 		];
 		if (tsNodes.includes(node.type)) {
-			if (parent.type === 'ExportNamedDeclaration') {
-				src.update(parent.start, parent.end, '');
+			if (['TSTypeAliasDeclaration', 'TSInterfaceDeclaration'].includes(node.type)) {
+				let start = node.start;
+
+				if (parent.type === 'ExportNamedDeclaration') {
+					start = parent.start;
+				}
+
+				removeNode(src, start, node.end, format);
 				return;
 			}
 
@@ -74,7 +85,7 @@ export function strip(source: string, options?: Options): string {
 		if (node.type === 'ImportDeclaration') {
 			// @ts-expect-error wrong
 			if (node.importKind === 'type') {
-				src.update(node.start, node.end, '');
+				removeNode(src, node.start, node.end, format);
 				return;
 			}
 
@@ -87,7 +98,7 @@ export function strip(source: string, options?: Options): string {
 
 			// if all the specifiers were type only remove the entire thing
 			if (remainingSpecifiers.length === 0) {
-				src.update(node.start, node.end, '');
+				removeNode(src, node.start, node.end, format);
 				return;
 			}
 
@@ -106,7 +117,7 @@ export function strip(source: string, options?: Options): string {
 		if (node.type === 'ExportNamedDeclaration') {
 			// @ts-expect-error wrong
 			if (node.exportKind === 'type') {
-				src.update(node.start, node.end, '');
+				removeNode(src, node.start, node.end, format);
 				return;
 			}
 
@@ -119,7 +130,7 @@ export function strip(source: string, options?: Options): string {
 
 			// if all the specifiers were type only remove the entire thing
 			if (remainingSpecifiers.length === 0) {
-				src.update(node.start, node.end, '');
+				removeNode(src, node.start, node.end, format);
 				return;
 			}
 
@@ -169,3 +180,39 @@ export function strip(source: string, options?: Options): string {
 
 	return src.toString();
 }
+
+/** Removes the entire node and any leading / trailing whitespace
+ *
+ * @param src
+ * @param start
+ * @param end
+ */
+function removeNode(src: MagicString, start: number, end: number, format: boolean) {
+	let newStart = start;
+	let newEnd = end;
+
+	if (format) {
+		newStart = 0;
+
+		// remove whitespace proceeding the node until the next newline / none whitespace character
+		for (let i = start - 1; i > -1; i--) {
+			if (/\S|\n/.test(src.original[i])) {
+				newStart = i + 1;
+				break;
+			}
+		}
+
+		// remove whitespace beyond the node until the proceeding whitespace of the next node
+		for (let i = end; i < src.original.length; i++) {
+			if (/\S/.test(src.original[i])) {
+				break;
+			}
+
+			if (src.original[i] === '\n') {
+				newEnd = i + 1;
+			}
+		}
+	}
+
+	src.update(newStart, newEnd, '');
+}

tests/cases/stip-prefix-assertion/js.svelte

@@ -1,5 +1,3 @@
 <script>
-    
-
     let thing = "foo";
 </script>

tests/cases/strip-func-binding-types/js.svelte

@@ -1,5 +1,4 @@
 <script>
-    
 </script>
 
 <input bind:value={() => {

tests/cases/strip-getter-setter-types/js.svelte

@@ -1,6 +1,4 @@
 <script>
-    
-
     let value = $state(0);
 </script>
 

tests/cases/strip-type-only-exports/js.svelte

@@ -1,11 +1,5 @@
 <script module>
-    
-    
-    
-    
     const FIVE = 5;
 
-    
-    
     export { FIVE };
 </script>

tests/cases/strips-interface/js.svelte

@@ -1,7 +1,3 @@
 <script>
-	
-
-    
-
     let { ...rest } = $props();
 </script>

tests/cases/strips-props/js.svelte

@@ -1,6 +1,4 @@
 <script>
-	
-
 	let { value } = $props();
 </script>