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🦕 Molt

[!Warning]
This project is still in early development. Expect inconveniences and breaking changes.

Molt is a Deno module to bump semvers in import specifiers, focused on consistency and maintainability. It uses deno_graph for dependency resolution, which enables us to avoid implementing custom logic or regex for each module registry.

Key Concepts

  • No regex to detect dependencies - Import specifiers of dependencies are discovered by the same parser as Deno runtime.
  • No custom logic for each registry - Latest versions of dependencies are obtained by redirects of fetch requests by module registries.
  • Module-first - The core logic is provided as versatile functions in a Deno module, which enables you to write the best scripts for your use cases.
  • Git-friendly - The operations can be easily divided into logical groups for subsequent git commits. A submodule and CLI for git operations are also provided.

Usage

Deno Module

API Reference (WIP)

Examples

Update all dependencies in a module and write the changes to local files
import {
  DependencyUpdate,
  FileUpdate,
} from "https://deno.land/x/molt@{VERSION}/mod.ts";

const updates = await DependencyUpdate.collect("./mod.ts", {
  importMap: "./deno.json",
});

const results = FileUpdate.collect(updates);
FileUpdate.writeAll(results);
Update all dependencies in a module and commit the changes to local git repository
import { DependencyUpdate } from "https://deno.land/x/molt@{VERSION}/mod.ts";
import { commitAll } from "https://deno.land/x/molt@{VERSION}/git/mod.ts";

const updates = await DependencyUpdate.collect("./mod.ts");

commitAll(updates, {
  groupBy: (dependency) => dependency.name,
  composeCommitMessage: ({ group, version }) =>
    `build(deps): bump ${group} to ${version!.to}`,
});

CLI

Although it is recommended to write your own scripts with the module, a pre-built CLI is also provided as cli.ts for convenience, which is supposed to cover most of the use cases.

Installation (optional)

The molt CLI can be installed globally with the following command:

deno install --allow-env --allow-read --allow-net --allow-write --allow-run=git\
--name=molt https://deno.land/x/molt/cli.ts

However, it is recommended to run the remote script directly through deno task for more precise control on permissions. Here’s an example deno.json:

{
  "tasks": {
    "run": "deno run --allow-env --allow-read --allow-net",
    "update": "deno task run --allow-write=. https://deno.land/x/molt/cli.ts update",
    "update:check": "deno task run https://deno.land/x/molt/cli.ts check",
    "update:commit": "deno task run --allow-write=. --allow-run=git https://deno.land/x/molt/cli.ts update --commit",
  },
}

Of course, you may use --allow-all instead at your own risk.

Update dependencies interactively

The most interactive interface is provided as check sub-command of cli.ts.

deno run --allow-env --allow-read --allow-net --allow-write=. --allow-run=git\
https://deno.land/x/molt/cli.ts check --import-map <file> <...entrypoints>

[!Note]
Molt CLI automatically uses import maps defined in deno.json or deno.jsonc if available.
You can’t, however, use import maps as an entrypoint.

Example: Just check
> deno run --allow-env --allow-net --allow-read\
https://deno.land/x/molt/cli.ts check src/fixtures/mod.ts 
🔎 Checking for updates...
💡 Found updates:

📦 node-emoji 1.0.0 => 2.1.0
  src/fixtures/mod.ts 1.0.0

📦 deno.land/x/deno_graph 0.50.0 => 0.55.0
  src/fixtures/mod.ts 0.50.0

📦 deno.land/std 0.200.0 => 0.202.0
  src/fixtures/mod.ts 0.200.0
  src/fixtures/lib.ts 0.200.0

? Choose an action › Abort

>
Example: Write changes to files
> deno run --allow-env --allow-net --allow-read --allow-write=.\
https://deno.land/x/molt/cli.ts check src/fixtures/mod.ts 
🔎 Checking for updates...
💡 Found updates:
    ...

? Choose an action › Write changes to local files

Writing changes...
💾 src/fixtures/mod.ts
💾 src/fixtures/lib.ts

>
Example: Commit changes to git
> deno run --allow-env --allow-net --allow-read --allow-write=. --allow-run=git\
https://deno.land/x/molt/cli.ts check src/fixtures/mod.ts 
🔎 Checking for updates...
💡 Found updates:
    ...

? Choose an action › Commit changes to git
? Run `deno task test` before each commit? › No

Committing changes...
📝 build(deps): update deno.land/std from 0.200.0 to 0.202.0
📝 build(deps): update deno.land/x/deno_graph from 0.50.0 to 0.55.0
📝 build(deps): update node-emoji from 1.0.0 to 2.1.0

>

Update dependencies non-interactively

The update sub-command of cli.ts is designed to be used in non-interactive environments, such as CI/CD pipelines.

Example: Update dependencies and write changes to files
deno run --allow-env --allow-read --allow-net --allow-write=.\
https://deno.land/x/molt/cli.ts update <...entrypoints>
Example: Update dependencies and commit changes to git
deno run --allow-env --allow-read --allow-net --allow-write=. --allow-run=git\
https://deno.land/x/molt/cli.ts update --commit <...entrypoints>

Limitations

The following limitations are imposed by the design of Molt:

  • Dependencies are always updated to the latest version. No version constraints are supported.
  • Dependencies in import specifiers are only targeted.

See issues for other known limitations.

Acknowledgments

Molt is inspired by prior works such as

and of full respect to the authors of these works.