Don't mutate error message (elastic#58452)

* fix: 🐛 don't mutate error object in-place This avoids mutating error thrown by an expression function in-place. The error might not even be an object, in which case mutating it will throw. * test: 💍 capture in test that thrown error is not mutated Co-authored-by: Elastic Machine <[email protected]>
jloleysens · Feb 25, 2020 · db05fb6 · db05fb6
1 parent afb5d8f
commit db05fb6
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diff --git a/src/plugins/expressions/common/execution/execution.test.ts b/src/plugins/expressions/common/execution/execution.test.ts
@@ -630,6 +630,7 @@ describe('Execution', () => {
           },
         });
         expect(node2.debug?.rawError).toBeInstanceOf(Error);
+        expect(node2.debug?.rawError).toEqual(new Error('foo'));
       });
 
       test('sets .debug object to expected shape', async () => {

diff --git a/src/plugins/expressions/common/execution/execution.ts b/src/plugins/expressions/common/execution/execution.ts
@@ -230,8 +230,8 @@ export class Execution<
         input = output;
       } catch (rawError) {
         const timeEnd: number = this.params.debug ? performance.now() : 0;
-        rawError.message = `[${fnName}] > ${rawError.message}`;
         const error = createError(rawError) as ExpressionValueError;
+        error.error.message = `[${fnName}] > ${error.error.message}`;
 
         if (this.params.debug) {
           (link as ExpressionAstFunction).debug = {
-Original file line number
+Diff line change
@@ Expand Up / @@ -630,6 +630,7 @@ describe('Execution', () => { @@
               },
             });
             expect(node2.debug?.rawError).toBeInstanceOf(Error);
+            expect(node2.debug?.rawError).toEqual(new Error('foo'));
           });
           test('sets .debug object to expected shape', async () => {
@@ Expand Down @@