fix: correct math.pi constant rewriting and code action range in Molang optimizations

- In `string.ts`: Don't append `()` for zero-argument FunctionCall nodes (e.g. `math.pi`)
  so that constants are serialized correctly without parentheses.
- In `nodes.ts`: Fix infinite loop in `getLastEndPosition` for FunctionCall with 0 args
  by returning early with the correct identifier length.
- In `nodes.ts`: Add `ExpressionNode.getStartPosition()` helper that finds the minimum
  (leftmost) source offset among all descendants of an expression node.
- In `registry.ts`: Use `OffsetWord` with the full expression range (from `getStartPosition`
  to `getLastEndPosition`) when adding optimization diagnostics, so code actions replace
  the correct text instead of just the operator and adjacent identifier.
- In `optimizations.test.ts`: Add regression test asserting that `5*3*math.pi`
  produces a replacement containing `math.pi` and not `math.pi()`.

Agent-Logs-Url: https://github.com/Blockception/minecraft-bedrock-language-server/sessions/c46da7a3-c138-4dfb-a355-ca41b9f597bc

Co-authored-by: DaanV2 <2393905+DaanV2@users.noreply.github.com>

Author: Copilot

ide/vscode/src/version.ts

@@ -1 +1 @@
-export const Version = "9.0.32";
+export const Version = "9.1.3";

package-lock.json

@@ -13549,7 +13549,8 @@
       "devDependencies": {
         "@eslint/js": "^10.0.1",
         "@types/eslint__js": "^9.14.0",
-        "@types/node": "^25.6.2",
+        "@types/jest": "^30.0.0",
+        "@types/node": "^25.7.0",
         "eslint": "^10.3.0",
         "rimraf": "^6.1.3",
         "ts-loader": "^9.5.0",
@@ -13558,6 +13559,23 @@
         "typescript-eslint": "^8.59.2"
       }
     },
+    "packages/molang/node_modules/@types/node": {
+      "version": "25.7.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.7.0.tgz",
+      "integrity": "sha512-z+pdZyxE+RTQE9AcboAZCb4otwcrvgHD+GlBpPgn0emDVt0ohrTMhAwlr2Wd9nZ+nihhYFxO2pThz3C5qSu2Eg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~7.21.0"
+      }
+    },
+    "packages/molang/node_modules/undici-types": {
+      "version": "7.21.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.21.0.tgz",
+      "integrity": "sha512-w9IMgQrz4O0YN1LtB7K5P63vhlIOvC7opSmouCJ+ZywlPAlO9gIkJ+otk6LvGpAs2wg4econaCz3TvQ9xPoyuQ==",
+      "dev": true,
+      "license": "MIT"
+    },
     "packages/project": {
       "name": "bc-minecraft-project",
       "version": "1.22.2-1",

packages/bedrock-diagnoser/src/diagnostics/molang/optimizations/registry.ts

@@ -1,4 +1,5 @@
 import { ExpressionNode, walk } from 'bc-minecraft-molang';
+import { OffsetWord } from 'bc-minecraft-bedrock-shared';
 import { DiagnosticsBuilder } from '../../../types';
 import { OptimizationCategory, OptimizationRule } from './framework';
 import { createConstantConditionCategory, createConstantFoldingCategory, createConstantResultCategory, createDivisionByZeroCategory, createDoubleNegationCategory, createIdentityOperationsCategory, createRedundantComparisonCategory, createRedundantUnaryCategory, createSelfCancellationCategory, createSelfDivisionCategory } from './rules';
@@ -63,10 +64,17 @@ export class OptimizationRegistry {
         result = [result];
       }
 
+      // Compute the full source range of the expression so the code action
+      // replacement targets the correct text.
+      const startOffset = ExpressionNode.getStartPosition(node);
+      const endOffset = ExpressionNode.getLastEndPosition(node);
+      const length = Math.max(1, endOffset - startOffset);
+      const nodeRange = OffsetWord.create('x'.repeat(length), startOffset);
+
       for (const optimizedNode of result) {
         const data = optimizedNode.replacement !== undefined ? { replacement: optimizedNode.replacement } : undefined;
         diagnoser.add(
-          node.position,
+          nodeRange,
           optimizedNode.message,
           optimizedNode.severity ?? rule.severity,
           optimizedNode.code ?? rule.code,

packages/bedrock-diagnoser/test/lib/diagnostics/molang/optimizations.test.ts

@@ -492,5 +492,17 @@ describe('Molang Optimization Diagnostics', () => {
       expect(diag).toBeDefined();
       expect(diag?.data).toEqual({ replacement: '6' });
     });
+
+    it('should not add parentheses to math constants like math.pi in replacement (regression)', () => {
+      const diagnoser = new TestDiagnoser();
+      diagnose_molang_syntax_line('5*3*math.pi', diagnoser);
+
+      const diag = diagnoser.items.find((d) => d.code === 'molang.optimization.constant-folding');
+      expect(diag).toBeDefined();
+      const replacement = (diag?.data as { replacement: string })?.replacement;
+      expect(replacement).toBeDefined();
+      expect(replacement).toContain('math.pi');
+      expect(replacement).not.toContain('math.pi()');
+    });
   });
 });

packages/molang/package.json

@@ -42,7 +42,8 @@
   "devDependencies": {
     "@eslint/js": "^10.0.1",
     "@types/eslint__js": "^9.14.0",
-    "@types/node": "^25.6.2",
+    "@types/jest": "^30.0.0",
+    "@types/node": "^25.7.0",
     "eslint": "^10.3.0",
     "rimraf": "^6.1.3",
     "ts-loader": "^9.5.0",

packages/molang/src/molang/syntax/nodes.ts

@@ -297,6 +297,9 @@ export namespace ExpressionNode {
           node = max(node.right, node.left);
           break;
         case NodeType.FunctionCall:
+          if (node.arguments.length === 0) {
+            return node.position + getIdentifier(node).length;
+          }
           const args = node.arguments;
           args.forEach((arg) => (node = max(node, arg)));
           break;
@@ -316,4 +319,18 @@ export namespace ExpressionNode {
   export function toString(node: ExpressionNode): string {
     return nodesToString(node);
   }
+
+  /**
+   * Gets the minimum (leftmost) character offset of an expression node and all its descendants.
+   * This is the true start of the expression in the source text.
+   */
+  export function getStartPosition(node: ExpressionNode): number {
+    let min = node.position;
+    const children = getChildern(node);
+    for (const child of children) {
+      const childMin = getStartPosition(child);
+      if (childMin < min) min = childMin;
+    }
+    return min;
+  }
 }

packages/molang/src/molang/syntax/string.ts

@@ -12,6 +12,7 @@ export function nodesToString(node: ExpressionNode): string {
       return `(${nodesToString(node.condition)} ? ${nodesToString(node.trueExpression)} : ${nodesToString(node.falseExpression!)})`;
     case NodeType.FunctionCall:
       const id = ExpressionNode.getIdentifier(node);
+      if (node.arguments.length === 0) return id;
       return `${id}(${node.arguments.map(nodesToString).join(', ')})`;
     case NodeType.Literal:
       return node.value;