perf: only create objects for completion items for svelte syntax once (#2900)

* only create objects for completion items for svelte syntax once

* Optimize completion items handling for Svelte syntax

* format

Author: MathiasWP

.changeset/sharp-jeans-attack.md

@@ -0,0 +1,5 @@
+---
+'svelte-language-server': patch
+---
+
+[perf]: avoid re-reacting completion items for svelte syntax every time `getCompletionsWithRegardToTriggerCharacter` is called

packages/language-server/src/plugins/svelte/features/getCompletions.ts

@@ -109,6 +109,48 @@ function getEventModifierCompletion(attributeContext: AttributeContext): Complet
     return CompletionList.create(items);
 }
 
+const atCompletionItems = createCompletionItems([
+    { tag: 'html', label: 'html' },
+    { tag: 'debug', label: 'debug' },
+    { tag: 'const', label: 'const' },
+    { tag: 'render', label: 'render' },
+    { tag: 'attach', label: 'attach' }
+]);
+
+const hashtagCompletionItems = createCompletionItems([
+    { tag: 'if', label: 'if', insertText: 'if $1}\n\t$2\n{/if' },
+    { tag: 'each', label: 'each', insertText: 'each $1 as $2}\n\t$3\n{/each' },
+    {
+        tag: 'await',
+        label: 'await :then',
+        insertText: 'await $1}\n\t$2\n{:then $3} \n\t$4\n{/await'
+    },
+    {
+        tag: 'await',
+        label: 'await then',
+        insertText: 'await $1 then $2}\n\t$3\n{/await'
+    },
+    { tag: 'key', label: 'key', insertText: 'key $1}\n\t$2\n{/key' },
+    { tag: 'snippet', label: 'snippet', insertText: 'snippet $1($2)}\n\t$3\n{/snippet' }
+]);
+
+const beginningAwaitOpenCompletionItems = createCompletionItems([
+    { tag: 'await', label: 'then' },
+    { tag: 'await', label: 'catch' }
+]);
+
+const beginningEachOpenCompletionItems = createCompletionItems([{ tag: 'each', label: 'else' }]);
+
+const beginningIfOpenCompletionItems = createCompletionItems([
+    { tag: 'if', label: 'else' },
+    { tag: 'if', label: 'else if' }
+]);
+
+const endAwaitOpenCompletionItems = createCompletionItems([{ tag: 'await', label: 'await' }]);
+const endEachOpenCompletionItems = createCompletionItems([{ tag: 'each', label: 'each' }]);
+const endIfOpenCompletionItems = createCompletionItems([{ tag: 'if', label: 'if' }]);
+const endKeyOpenCompletionItems = createCompletionItems([{ tag: 'key', label: 'key' }]);
+
 /**
  * Get completions with regard to trigger character.
  */
@@ -118,46 +160,19 @@ function getCompletionsWithRegardToTriggerCharacter(
     offset: number
 ) {
     if (triggerCharacter === '@') {
-        return createCompletionItems([
-            { tag: 'html', label: 'html' },
-            { tag: 'debug', label: 'debug' },
-            { tag: 'const', label: 'const' },
-            { tag: 'render', label: 'render' },
-            { tag: 'attach', label: 'attach' }
-        ]);
+        return atCompletionItems;
     }
 
     if (triggerCharacter === '#') {
-        return createCompletionItems([
-            { tag: 'if', label: 'if', insertText: 'if $1}\n\t$2\n{/if' },
-            { tag: 'each', label: 'each', insertText: 'each $1 as $2}\n\t$3\n{/each' },
-            {
-                tag: 'await',
-                label: 'await :then',
-                insertText: 'await $1}\n\t$2\n{:then $3} \n\t$4\n{/await'
-            },
-            {
-                tag: 'await',
-                label: 'await then',
-                insertText: 'await $1 then $2}\n\t$3\n{/await'
-            },
-            { tag: 'key', label: 'key', insertText: 'key $1}\n\t$2\n{/key' },
-            { tag: 'snippet', label: 'snippet', insertText: 'snippet $1($2)}\n\t$3\n{/snippet' }
-        ]);
+        return hashtagCompletionItems;
     }
 
     if (triggerCharacter === ':') {
         return showCompletionWithRegardsToOpenedTags(
             {
-                awaitOpen: createCompletionItems([
-                    { tag: 'await', label: 'then' },
-                    { tag: 'await', label: 'catch' }
-                ]),
-                eachOpen: createCompletionItems([{ tag: 'each', label: 'else' }]),
-                ifOpen: createCompletionItems([
-                    { tag: 'if', label: 'else' },
-                    { tag: 'if', label: 'else if' }
-                ])
+                awaitOpen: beginningAwaitOpenCompletionItems,
+                eachOpen: beginningEachOpenCompletionItems,
+                ifOpen: beginningIfOpenCompletionItems
             },
             svelteDoc,
             offset
@@ -167,10 +182,10 @@ function getCompletionsWithRegardToTriggerCharacter(
     if (triggerCharacter === '/') {
         return showCompletionWithRegardsToOpenedTags(
             {
-                awaitOpen: createCompletionItems([{ tag: 'await', label: 'await' }]),
-                eachOpen: createCompletionItems([{ tag: 'each', label: 'each' }]),
-                ifOpen: createCompletionItems([{ tag: 'if', label: 'if' }]),
-                keyOpen: createCompletionItems([{ tag: 'key', label: 'key' }])
+                awaitOpen: endAwaitOpenCompletionItems,
+                eachOpen: endEachOpenCompletionItems,
+                ifOpen: endIfOpenCompletionItems,
+                keyOpen: endKeyOpenCompletionItems
             },
             svelteDoc,
             offset