Merge pull request #458 from senacor/bugfix/huge_memory_consumption

Fix huge memory consumption for logging

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## 3.1.2 (13.12.2024)
+* Use default limits for array length, object depth or string length for logging (reverts change from version 3.1.1) as this could cause a huge memory consumption in some cases
+* Use `JSON.stringify` to log objects that have a `toJSON` method
+
 ## 3.1.1 (15.11.2024)
 * Do not limit array length, object depth or string length for logging
 

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@senacor/azure-function-middleware",
-    "version": "3.1.1",
+    "version": "3.1.2",
     "description": "Middleware for azure functions to handle authentication, authorization, error handling and logging",
     "main": "dist/index.js",
     "types": "dist/index.d.ts",

src/util/stringify.test.ts

@@ -25,7 +25,17 @@ describe('stringify should', () => {
         expect(stringify('Test', 2, { message: 'World' })).toBe("Test 2 { message: 'World' }");
     });
 
-    it('print all array items', () => {
-        expect(stringify(Array(250).fill(1)).match(/1/g)?.length).toBe(250);
+    it('do not print all items of large arrays', () => {
+        expect(stringify(Array(250).fill(1)).match(/1/g)?.length).toBeLessThan(250);
+    });
+
+    it('use toJSON function if available', () => {
+        const input = {
+            toJSON: () => ({
+                value: 42,
+            }),
+        };
+
+        expect(stringify(input)).toEqual('{"value":42}');
     });
 });

src/util/stringify.ts

@@ -9,5 +9,17 @@ function stringifyValue(value: unknown): string {
         return value;
     }
 
-    return inspect(value, { depth: null, maxArrayLength: null, maxStringLength: null });
+    if (isJsonSerializable(value)) {
+        return JSON.stringify(value);
+    }
+
+    return inspect(value);
+}
+
+type JsonSerializable = {
+    toJSON: () => unknown;
+};
+
+function isJsonSerializable(value: unknown): value is JsonSerializable {
+    return typeof (value as JsonSerializable)?.toJSON === 'function';
 }

src/validation.ts

@@ -3,7 +3,6 @@ import { AnySchema } from 'joi';
 
 import { ApplicationError } from './error';
 import { BeforeExecutionFunction, MiddlewareResult, PostExecutionFunction, isErrorResult } from './middleware';
-import { stringify } from './util/stringify';
 
 type ValidationOptions = Partial<{
     transformErrorMessage: (message: string) => unknown;
@@ -39,8 +38,8 @@ export function requestValidation(schema: AnySchema, opts?: ValidationOptions):
             if (validationResult && validationResult.error) {
                 context.error(
                     `The request did not match the given schema.${
-                        printRequest ? stringify(toBeValidatedContent) : ''
-                    }: ${stringify(validationResult)}`,
+                        printRequest ? JSON.stringify(toBeValidatedContent) : ''
+                    }: ${JSON.stringify(validationResult)}`,
                 );
 
                 if (shouldThrowOnValidationError) {
@@ -93,8 +92,8 @@ export function responseValidation(schema: AnySchema, opts?: ValidationOptions):
         if (validationResult && validationResult.error) {
             context.error(
                 `The response did not match the given schema.${
-                    printResponse ? stringify(toBeValidatedContent) : ''
-                }: ${stringify(validationResult)}`,
+                    printResponse ? JSON.stringify(toBeValidatedContent) : ''
+                }: ${JSON.stringify(validationResult)}`,
             );
 
             if (shouldThrowOnValidationError) {