protobufjs-cli

protobufjs-cli
==============

Command line interface (CLI) for protobuf.js.

This can be used to translate between file formats and to generate static code as well as TypeScript definitions.

* pbjs for JavaScript
* pbts for TypeScript
* Reflection vs. static code
* Command line API

$3

``
Translates between file formats and generates static code.

-t, --target Specifies the target format. Also accepts a path to require a custom target.

json JSON representation
json-module JSON representation as a module
proto2 Protocol Buffers, Version 2
proto3 Protocol Buffers, Version 3
static Static code without reflection (non-functional on its own)
static-module Static code without reflection as a module

-p, --path Adds a directory to the include path.

-o, --out Saves to a file instead of writing to stdout.

--sparse Exports only those types referenced from a main file (experimental).

Module targets only:

-w, --wrap Specifies the wrapper to use. Also accepts a path to require a custom wrapper.

default Default wrapper supporting both CommonJS and AMD
commonjs CommonJS wrapper
amd AMD wrapper
es6 ES6 wrapper (implies --es6)
closure A closure adding to protobuf.roots where protobuf is a global

-r, --root Specifies an alternative protobuf.roots name.

-l, --lint Linter configuration. Defaults to protobuf.js-compatible rules:

eslint-disable block-scoped-var, no-redeclare, no-control-regex, no-prototype-builtins

--es6 Enables ES6 syntax (const/let instead of var)

Proto sources only:

--keep-case Keeps field casing instead of converting to camel case.

Static targets only:

--no-create Does not generate create functions used for reflection compatibility.
--no-encode Does not generate encode functions.
--no-decode Does not generate decode functions.
--no-verify Does not generate verify functions.
--no-convert Does not generate convert functions like from/toObject
--no-delimited Does not generate delimited encode/decode functions.
--no-beautify Does not beautify generated code.
--no-comments Does not output any JSDoc comments.
--no-service Does not output service classes.

--force-long Enforces the use of 'Long' for s-/u-/int64 and s-/fixed64 fields.
--force-number Enforces the use of 'number' for s-/u-/int64 and s-/fixed64 fields.
--force-message Enforces the use of message instances instead of plain objects.

--null-defaults Default value for optional fields is null instead of zero value.
--null-semantics Make nullable fields match protobuf semantics (overrides --null-defaults).

usage: pbjs [options] file1.proto file2.json ... (or pipe) other | pbjs [options] -
`

For production environments it is recommended to bundle all your .proto files to a single .json file, which minimizes the number of network requests and avoids any parser overhead (hint: works with just the light library):

`
$> pbjs -t json file1.proto file2.proto > bundle.json
`

Now, either include this file in your final bundle:

`js
var root = protobuf.Root.fromJSON(require("./bundle.json"));
`

or load it the usual way:

`js
protobuf.load("bundle.json", function(err, root) {
...
});
`

Generated static code, on the other hand, works with just the minimal library. For example

`
$> pbjs -t static-module -w commonjs -o compiled.js file1.proto file2.proto
`

will generate static code for definitions within file1.proto and file2.proto to a CommonJS module compiled.js.

ProTip! Documenting your .proto files with /* ... /-blocks or (trailing) /// ... lines translates to generated static code.

$3

`
Generates TypeScript definitions from annotated JavaScript files.

-o, --out Saves to a file instead of writing to stdout.

-g, --global Name of the global object in browser environments, if any.

--no-comments Does not output any JSDoc comments.

Internal flags:

-n, --name Wraps everything in a module of the specified name.

-m, --main Whether building the main library without any imports.

usage: pbts [options] file1.js file2.js ... (or) other | pbts [options] -
`

Picking up on the example above, the following not only generates static code to a CommonJS module compiled.js but also its respective TypeScript definitions to compiled.d.ts:

`
$> pbjs -t static-module -w commonjs -o compiled.js file1.proto file2.proto
$> pbts -o compiled.d.ts compiled.js
`

Additionally, TypeScript definitions of static modules are compatible with their reflection-based counterparts (i.e. as exported by JSON modules), as long as the following conditions are met:

1. Instead of using new SomeMessage(...), always use SomeMessage.create(...) because reflection objects do not provide a constructor.
2. Types, services and enums must start with an uppercase letter to become available as properties of the reflected types as well (i.e. to be able to use MyMessage.MyEnum instead of root.lookup("MyMessage.MyEnum")).

For example, the following generates a JSON module bundle.js and a bundle.d.ts, but no static code:

`
$> pbjs -t json-module -w commonjs -o bundle.js file1.proto file2.proto
$> pbjs -t static-module file1.proto file2.proto | pbts -o bundle.d.ts -
`

$3

While using .proto files directly requires the full library respectively pure reflection/JSON the light library, pretty much all code but the relatively short descriptors is shared.

Static code, on the other hand, requires just the minimal library, but generates additional source code without any reflection features. This also implies that there is a break-even point where statically generated code becomes larger than descriptor-based code once the amount of code generated exceeds the size of the full respectively light library.

There is no significant difference performance-wise as the code generated statically is pretty much the same as generated at runtime and both are largely interchangeable as seen in the previous section.

| Source | Library | Advantages | Tradeoffs
|--------|---------|------------|-----------
| .proto | full | Easily editable
Interoperability with other libraries
No compile step | Some parsing and possibly network overhead
| JSON | light | Easily editable
No parsing overhead
Single bundle (no network overhead) | protobuf.js specific
Has a compile step
| static | minimal | Works where eval access is restricted
Fully documented
Small footprint for small protos | Can be hard to edit
No reflection
Has a compile step

$3

Both utilities can be used programmatically by providing command line arguments and a callback to their respective main functions:

`js
var pbjs = require("protobufjs-cli/pbjs"); // or require("protobufjs-cli").pbjs / .pbts

pbjs.main([ "--target", "json-module", "path/to/myproto.proto" ], function(err, output) {
if (err)
throw err;
// do something with output
});
``

License: BSD 3-Clause License