V2: Add DescEnum.value (#927)

Author: timostamm

packages/bundle-size/README.md

@@ -16,11 +16,11 @@ usually do. We repeat this for an increasing number of files.
 
 | code generator      | files | bundle size |  minified | compressed |
 | ------------------- | ----: | ----------: | --------: | ---------: |
-| protobuf-es         |     1 |   125,855 b |  65,617 b |   15,259 b |
-| protobuf-es         |     4 |   128,044 b |  67,125 b |   15,961 b |
-| protobuf-es         |     8 |   130,806 b |  68,896 b |   16,416 b |
-| protobuf-es         |    16 |   141,256 b |  76,877 b |   18,761 b |
-| protobuf-es         |    32 |   169,047 b |  98,895 b |   24,239 b |
+| protobuf-es         |     1 |   125,880 b |  65,631 b |   15,280 b |
+| protobuf-es         |     4 |   128,069 b |  67,139 b |   15,961 b |
+| protobuf-es         |     8 |   130,831 b |  68,910 b |   16,456 b |
+| protobuf-es         |    16 |   141,281 b |  76,891 b |   18,790 b |
+| protobuf-es         |    32 |   169,072 b |  98,909 b |   24,236 b |
 | protobuf-javascript |     1 |   334,193 b | 255,820 b |   42,481 b |
 | protobuf-javascript |     4 |   360,861 b | 271,092 b |   43,912 b |
 | protobuf-javascript |     8 |   382,904 b | 283,409 b |   45,038 b |

packages/bundle-size/chart.svg

@@ -290,3 +290,14 @@ describe("GenMessage.field", () => {
     proto3_ts.Proto3MessageSchema.field.foo;
   });
 });
+
+describe("GenDescEnum.value", () => {
+  test("is type safe", () => {
+    const val = proto3_ts.Proto3EnumSchema.value[proto3_ts.Proto3Enum.YES];
+    expect(val.number).toBe(1);
+    expect(val.name).toBe("PROTO3_ENUM_YES");
+    expect(val.localName).toBe("YES");
+    // @ts-expect-error TS7053: Element implicitly has an any type because expression of type 77 can't be used to index type Record<Proto3Enum, DescEnumValue>
+    proto3_ts.Proto3EnumSchema.value[77];
+  });
+});

packages/protobuf-test/src/generate-code.test.ts

@@ -21,11 +21,10 @@ import type { JsonValue } from "../json-value.js";
  *
  * @private
  */
-export function enumDesc<Shape, JsonType extends JsonValue = JsonValue>(
-  file: DescFile,
-  path: number,
-  ...paths: number[]
-): GenEnum<Shape, JsonType> {
+export function enumDesc<
+  Shape extends number,
+  JsonType extends JsonValue = JsonValue,
+>(file: DescFile, path: number, ...paths: number[]): GenEnum<Shape, JsonType> {
   if (paths.length == 0) {
     return file.enums[path] as GenEnum<Shape, JsonType>;
   }

packages/protobuf/src/codegenv1/enum.ts

@@ -15,6 +15,7 @@
 import type { Message } from "../types.js";
 import type {
   DescEnum,
+  DescEnumValue,
   DescExtension,
   DescField,
   DescFile,
@@ -54,9 +55,11 @@ export type GenMessage<RuntimeShape extends Message, JsonType = JsonValue> =
  * @private
  */
 export type GenEnum<
-  RuntimeShape,
+  RuntimeShape extends number,
   JsonType extends JsonValue = JsonValue,
-> = DescEnum & brandv1<RuntimeShape, JsonType>;
+> = Omit<DescEnum, "value"> & {
+  value: Record<RuntimeShape, DescEnumValue>;
+} & brandv1<RuntimeShape, JsonType>;
 
 /**
  * Describes an extension in a protobuf source file.

packages/protobuf/src/codegenv1/types.ts

@@ -171,6 +171,10 @@ export interface DescEnum {
    * Values declared for this enumeration.
    */
   readonly values: DescEnumValue[];
+  /**
+   * All values of this enum by their number.
+   */
+  readonly value: Record<number, DescEnumValue>;
   /**
    * A prefix shared by all enum values.
    * For example, `my_enum_` for `enum MyEnum {MY_ENUM_A=0; MY_ENUM_B=1;}`

packages/protobuf/src/descriptors.ts

@@ -599,6 +599,7 @@ function addEnum(
     open: true,
     name: proto.name,
     typeName: makeTypeName(proto, parent, file),
+    value: {},
     values: [],
     sharedPrefix,
     toString(): string {
@@ -609,20 +610,24 @@ function addEnum(
   reg.add(desc);
   proto.value.forEach((proto) => {
     const name = proto.name;
-    desc.values.push({
-      kind: "enum_value",
-      proto,
-      deprecated: proto.options?.deprecated ?? false,
-      parent: desc,
-      name: proto.name,
-      localName: safeObjectProperty(
-        sharedPrefix == undefined ? name : name.substring(sharedPrefix.length),
-      ),
-      number: proto.number,
-      toString() {
-        return `enum value ${desc.typeName}.${this.name}`;
-      },
-    });
+    desc.values.push(
+      (desc.value[proto.number] = {
+        kind: "enum_value" as const,
+        proto,
+        deprecated: proto.options?.deprecated ?? false,
+        parent: desc,
+        name,
+        localName: safeObjectProperty(
+          sharedPrefix == undefined
+            ? name
+            : name.substring(sharedPrefix.length),
+        ),
+        number: proto.number,
+        toString() {
+          return `enum value ${desc.typeName}.${name}`;
+        },
+      }),
+    );
   });
   (parent?.nestedEnums ?? file.enums).push(desc);
 }

packages/protobuf/src/registry.ts

@@ -14,6 +14,7 @@
 
 import {
   type DescEnum,
+  type DescEnumValue,
   type DescField,
   type DescMessage,
   ScalarType,
@@ -169,7 +170,7 @@ export function enumToJson<Desc extends DescEnum>(
   if (descEnum.typeName == "google.protobuf.NullValue") {
     return null as EnumJsonType<Desc>;
   }
-  const name = descEnum.values.find((v) => v.number === value)?.name;
+  const name = (descEnum.value[value] as DescEnumValue | undefined)?.name;
   if (name === undefined) {
     throw new Error(
       `${String(value)} is not a value in ${descEnum.toString()}`,
@@ -308,7 +309,7 @@ function enumToJsonInternal(
   if (enumAsInteger) {
     return value;
   }
-  const val = desc.values.find((v) => v.number == value);
+  const val = desc.value[value] as DescEnumValue | undefined;
   return val?.name ?? value; // if we don't know the enum value, just return the number
 }
 

packages/protobuf/src/to-json.ts

@@ -63,7 +63,7 @@ export type EnumShape<Desc extends DescEnum> =
  * Extract the enum JSON type from a enum descriptor.
  */
 export type EnumJsonType<Desc extends DescEnum> =
-  Desc extends GenEnum<unknown, infer JsonType> ? JsonType : string | null;
+  Desc extends GenEnum<number, infer JsonType> ? JsonType : string | null;
 
 /**
  * Extract the value type from an extension descriptor.