@bufbuild/protoc-gen-es

The code generator plugin for Protocol Buffers for ECMAScript. Learn more about the project at github.com/bufbuild/protobuf-es.

Installation

protoc-gen-es generates base types—messages and enumerations—from your Protocol Buffer schema. The generated code requires the runtime library @bufbuild/protobuf. It's compatible with Protocol Buffer compilers like buf and protoc.

To install the plugin and the runtime library, run:

npm install --save-dev @bufbuild/protoc-gen-es
npm install @bufbuild/protobuf

We use peer dependencies to ensure that the code generator and runtime library are compatible with each other. Note that npm installs them automatically, but Yarn and pnpm do not.

Generating code

With buf

npm install --save-dev @bufbuild/buf

Add a new buf.gen.yaml configuration file:

# Learn more: https://buf.build/docs/configuration/v2/buf-gen-yaml
version: v2
plugins:
  # This will invoke protoc-gen-es and write output to src/gen
  - local: protoc-gen-es
    out: src/gen
    opt:
      # Add more plugin options here
      - target=ts

To generate code for all Protobuf files within your project, run:

npx buf generate

Note that buf can generate from various inputs, not just local Protobuf files.

With protoc

PATH=$PATH:$(pwd)/node_modules/.bin \
  protoc -I . \
  --es_out src/gen \
  --es_opt target=ts \
  a.proto b.proto c.proto

Note that node_modules/.bin needs to be added to the $PATH so that the Protobuf compiler can find the plugin. This happens automatically with npm scripts.

If you use Yarn, versions v2 and above don't use a node_modules directory, so you need to change the variable a bit:

PATH=$(dirname $(yarn bin protoc-gen-es)):$PATH

Plugin options

target

This option controls whether the plugin generates JavaScript, TypeScript, or TypeScript declaration files. Possible values:

• target=js: Generates a _pb.js file for every .proto input file.
• target=ts: Generates a _pb.ts file for every .proto input file.
• target=dts: Generates a _pb.d.ts file for every .proto input file.

You can pass multiple values by separating them with +—for example, target=js+dts.

By default, it generates JavaScript and TypeScript declaration files, which produces the smallest code size and is the most compatible with various bundler configurations. If you prefer to generate TypeScript, use target=ts.

import_extension

By default, protoc-gen-es doesn't add file extensions to import paths. However, some environments require an import extension. For example, using ECMAScript modules in Node.js requires the .js extension, and Deno requires .ts. With this plugin option, you can add .js/.ts extensions in import paths with the given value. Possible values:

• import_extension=none: Doesn't add an extension. (Default)
• import_extension=js: Adds the .js extension.
• import_extension=ts. Adds the .ts extension.

js_import_style

By default, protoc-gen-es generates ECMAScript import and export statements. For use cases where CommonJS is difficult to avoid, this option can be used to generate CommonJS require() calls. Possible values:

• js_import_style=module: Generates ECMAScript import/export statements. (Default)
• js_import_style=legacy_commonjs: Generates CommonJS require() calls.

keep_empty_files=true

By default, protoc-gen-es omits empty files from the plugin output. This option disables pruning of empty files to allow for smooth interoperation with Bazel and similar tooling that requires all output files to be declared ahead of time. Unless you use Bazel, you probably don't need this option.

ts_nocheck=true

protoc-gen-es generates valid TypeScript for current versions of the TypeScript compiler with standard settings. If you use compiler settings that yield an error for generated code, setting this option generates an annotation at the top of each file to skip type checks: // @ts-nocheck.

json_types=true

Generates JSON types for every Protobuf message and enumeration. Calling toJson() automatically returns the JSON type if available. Learn more about JSON types.