Simplify createOmitPropertiesSerializer

src/serializers/index.ts

@@ -1,8 +1,8 @@
 import type pino from 'pino';
 import { err, errWithCause } from 'pino-std-serializers';
 
-import { omitProperties } from './omitProperties';
 import { createOmitPropertiesSerializer } from './omitPropertiesSerializer';
+import type { SerializerFn } from './types';
 
 export const defaultOmitHeaderNames = [
   'x-envoy-attempt-count',
@@ -45,19 +45,17 @@ const isObject = (value: unknown): boolean => {
   return value != null && (type === 'object' || type === 'function');
 };
 
-const createReqSerializer = (opts: SerializerOptions) => (request: Request) =>
-  isObject(request)
-    ? {
-        method: request.method,
-        url: request.url,
-        headers: omitProperties(
-          request.headers,
-          opts.omitHeaderNames ?? defaultOmitHeaderNames,
-        ),
-        remoteAddress: request?.socket?.remoteAddress,
-        remotePort: request?.socket?.remotePort,
-      }
-    : request;
+const createReqSerializer =
+  (serializeHeaders: SerializerFn) => (request: Request) =>
+    isObject(request)
+      ? {
+          method: request.method,
+          url: request.url,
+          headers: serializeHeaders(request.headers),
+          remoteAddress: request?.socket?.remoteAddress,
+          remotePort: request?.socket?.remotePort,
+        }
+      : request;
 
 const res = (response: Response) =>
   isObject(response)
@@ -70,15 +68,17 @@ const res = (response: Response) =>
 export const createSerializers = (
   opts: SerializerOptions & Pick<pino.LoggerOptions, 'serializers'>,
 ) => {
-  const omitHeaderNamesSerializer = createOmitPropertiesSerializer('headers', {
-    omitPropertyNames: opts.omitHeaderNames ?? defaultOmitHeaderNames,
-  });
-  return {
+  const serializeHeaders = createOmitPropertiesSerializer(
+    opts.omitHeaderNames ?? defaultOmitHeaderNames,
+  );
+
+  const serializers = {
     err,
     errWithCause,
-    req: createReqSerializer(opts),
+    req: createReqSerializer(serializeHeaders),
     res,
-    ...omitHeaderNamesSerializer,
-    ...opts.serializers,
-  };
+    headers: serializeHeaders,
+  } satisfies pino.LoggerOptions['serializers'];
+
+  return serializers;
 };

src/serializers/omitPropertiesSerializer.test.ts

@@ -8,21 +8,6 @@ import { createOmitPropertiesSerializer } from './omitPropertiesSerializer';
 
 const omitPropertyNamesBase = ['remove-prop', 'remove.prop'];
 
-it.each`
-  scenario       | topLevelPropertyName
-  ${'undefined'} | ${undefined}
-  ${'null'}      | ${null}
-`(
-  'returns empty object when topLevelPropertyName is $scenario',
-  ({ topLevelPropertyName }) => {
-    const serializer = createOmitPropertiesSerializer(topLevelPropertyName, {
-      omitPropertyNames: [...omitPropertyNamesBase],
-    });
-
-    expect(serializer).toStrictEqual({});
-  },
-);
-
 it.each`
   scenario                  | omitPropertyNames
   ${'undefined'}            | ${undefined}
@@ -32,20 +17,16 @@ it.each`
 `(
   'returns empty object when omitPropertyNames is $scenario',
   ({ omitPropertyNames }) => {
-    const serializer = createOmitPropertiesSerializer('main', {
-      omitPropertyNames,
-    });
+    const serializer = createOmitPropertiesSerializer(omitPropertyNames);
 
-    expect(serializer).toStrictEqual({});
+    expect(serializer({})).toStrictEqual({});
   },
 );
 
 it('returns object with named property containing function', () => {
-  const serializer = createOmitPropertiesSerializer('main', {
-    omitPropertyNames: [...omitPropertyNamesBase],
-  });
+  const serializer = createOmitPropertiesSerializer(omitPropertyNamesBase);
 
-  expect(serializer).toStrictEqual({ main: expect.any(Function) });
+  expect(serializer).toStrictEqual(expect.any(Function));
 });
 
 const sink = () =>
@@ -71,9 +52,7 @@ function once(emitter: Transform, name: string) {
 }
 
 it('omits properties from logged object', async () => {
-  const serializer = createOmitPropertiesSerializer('main', {
-    omitPropertyNames: [...omitPropertyNamesBase],
-  });
+  const serializer = createOmitPropertiesSerializer(omitPropertyNamesBase);
 
   const input = {
     main: {
@@ -112,9 +91,7 @@ it.each`
 `(
   'does nothing when top-level property is $scenario',
   async ({ value, expected }) => {
-    const serializer = createOmitPropertiesSerializer('main', {
-      omitPropertyNames: ['keepProp'],
-    });
+    const serializer = createOmitPropertiesSerializer(['keepProp']);
 
     const input = {
       main: value,

src/serializers/omitPropertiesSerializer.ts

@@ -1,38 +1,19 @@
 import { omitProperties } from './omitProperties';
+import type { SerializerFn } from './types';
 
-export interface OmitPropertiesSerializerOptions {
+export const createOmitPropertiesSerializer = (
   /**
    * A list of properties that should not be logged.
    */
-  omitPropertyNames: string[];
-}
-
-type OmitHeaderNamesFn = (record: unknown) => unknown;
-type OmitHeaderNamesSerializer = Record<string, OmitHeaderNamesFn>;
+  properties: string[],
+): SerializerFn => {
+  const uniquePropertySet = new Set(properties);
 
-/** Creates a serializer that operates on the logged object's top-level property named `topLevelPropertyName`
- *  and omits the properties listed in `options.omitPropertyNames`.
- *  @param topLevelPropertyName - The name of the root property on the logged object that to omit properties from.
- *  @param options - Options for the serializer.
- */
-export const createOmitPropertiesSerializer = (
-  topLevelPropertyName: string,
-  options: OmitPropertiesSerializerOptions,
-): OmitHeaderNamesSerializer => {
-  const propertyNames = [...new Set(options.omitPropertyNames ?? [])].filter(
-    (propertyName) => typeof propertyName === 'string',
-  );
-
-  if (
-    !topLevelPropertyName ||
-    typeof topLevelPropertyName !== 'string' ||
-    topLevelPropertyName.length === 0 ||
-    propertyNames.length === 0
-  ) {
-    return {};
+  if (uniquePropertySet.size === 0) {
+    return (input) => input;
   }
 
-  return {
-    [topLevelPropertyName]: (record) => omitProperties(record, propertyNames),
-  };
+  const uniqueProperties = Array.from(uniquePropertySet);
+
+  return (input) => omitProperties(input, uniqueProperties);
 };

src/serializers/types.ts

@@ -0,0 +1 @@
+export type SerializerFn = (input: unknown) => unknown;