fix: adjust snippet code generation for new AST shape (#2282)

Snippets can now take one or more parameters, and their AST shape has changed as a consequence. Adjust it accordingly.
#2281

Author: dummdidumm

packages/svelte2tsx/src/htmlxtojsx_v2/nodes/EachBlock.ts

@@ -27,8 +27,8 @@ export function handleEach(str: MagicString, eachBlock: BaseNode): void {
     const containsComma = str.original
         .substring(eachBlock.expression.start, eachBlock.expression.end)
         .includes(',');
-    const expressionEnd = getEnd(eachBlock.expression, str);
-    const contextEnd = getEnd(eachBlock.context, str);
+    const expressionEnd = getEnd(eachBlock.expression);
+    const contextEnd = getEnd(eachBlock.context);
     const arrayAndItemVarTheSame =
         str.original.substring(eachBlock.expression.start, expressionEnd) ===
         str.original.substring(eachBlock.context.start, contextEnd);
@@ -78,8 +78,6 @@ export function handleEach(str: MagicString, eachBlock: BaseNode): void {
 /**
  * Get the end of the node, excluding the type annotation
  */
-function getEnd(node: any, str: MagicString) {
-    return node.typeAnnotation
-        ? str.original.lastIndexOf(':', node.typeAnnotation.start)
-        : node.end;
+function getEnd(node: any) {
+    return node.typeAnnotation?.start ?? node.end;
 }

packages/svelte2tsx/src/htmlxtojsx_v2/nodes/SnippetBlock.ts

@@ -43,17 +43,26 @@ export function handleSnippet(
     );
 
     const startEnd =
-        str.original.indexOf('}', snippetBlock.context?.end || snippetBlock.expression.end) + 1;
+        str.original.indexOf(
+            '}',
+            // context was the first iteration in a .next release, remove at some point
+            snippetBlock.context?.end ||
+                snippetBlock.parameters?.at(-1)?.end ||
+                snippetBlock.expression.end
+        ) + 1;
 
     if (isImplicitProp) {
         str.overwrite(snippetBlock.start, snippetBlock.expression.start, '', { contentOnly: true });
         const transforms: TransformationArray = ['('];
-        if (snippetBlock.context) {
-            transforms.push([snippetBlock.context.start, snippetBlock.context.end]);
-            str.overwrite(snippetBlock.expression.end, snippetBlock.context.start, '', {
+        if (snippetBlock.context || snippetBlock.parameters?.length) {
+            // context was the first iteration in a .next release, remove at some point
+            const start = snippetBlock.context?.start || snippetBlock.parameters?.[0].start;
+            const end = snippetBlock.context?.end || snippetBlock.parameters.at(-1).end;
+            transforms.push([start, end]);
+            str.overwrite(snippetBlock.expression.end, start, '', {
                 contentOnly: true
             });
-            str.overwrite(snippetBlock.context.end, startEnd, '', { contentOnly: true });
+            str.overwrite(end, startEnd, '', { contentOnly: true });
         } else {
             str.overwrite(snippetBlock.expression.end, startEnd, '', { contentOnly: true });
         }
@@ -64,15 +73,27 @@ export function handleSnippet(
             transforms
         );
     } else {
-        const generic = snippetBlock.context
-            ? snippetBlock.context.typeAnnotation
+        let generic = '';
+        // context was the first iteration in a .next release, remove at some point
+        if (snippetBlock.context) {
+            generic = snippetBlock.context.typeAnnotation
                 ? `<${str.original.slice(
-                      snippetBlock.context.typeAnnotation.start,
+                      snippetBlock.context.typeAnnotation.start + 1,
                       snippetBlock.context.typeAnnotation.end
                   )}>`
                 : // slap any on to it to silence "implicit any" errors; JSDoc people can't add types to snippets
-                  '<any>'
-            : '';
+                  '<any>';
+        } else if (snippetBlock.parameters?.length) {
+            generic = `<[${snippetBlock.parameters
+                .map((p) =>
+                    p.typeAnnotation
+                        ? str.original.slice(p.typeAnnotation.start + 1, p.typeAnnotation.end)
+                        : // slap any on to it to silence "implicit any" errors; JSDoc people can't add types to snippets
+                          'any'
+                )
+                .join(', ')}]>`;
+        }
+
         const typeAnnotation = surroundWithIgnoreComments(`: import('svelte').Snippet${generic}`);
         const transforms: TransformationArray = [
             'var ',

packages/svelte2tsx/test/htmlx2jsx/samples/snippet.v5/expected-svelte5.js

@@ -1,4 +1,4 @@
- var foo/*Ωignore_startΩ*/: import('svelte').Snippet<any>/*Ωignore_endΩ*/ = (x) => {
+ var foo/*Ωignore_startΩ*/: import('svelte').Snippet<[any]>/*Ωignore_endΩ*/ = (x) => {
 	 { svelteHTML.createElement("div", {}); x; }
 return __sveltets_2_any(0)};