🦕 Molt

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

A Deno module to update dependencies of Deno projects, using deno_graph for dependency resolution and parsing.

Key Concepts

“Traditional” dependency management tools for Deno projects use custom regex and logic for each module registry (deno.land, npm, esm.sh, ..) to find updates. This approach is not robust and requires a lot of maintenance effort.

Molt avoids implementing such custom logic as much as possible by using deno_graph to achieve better consistency and maintainability:

No regex to parse import statements - Dependencies of modules are discovered by the same routine as Deno CLI.
No custom logic for each registry - Latest versions of dependencies are obtained by the module resolution logic of Deno CLI and redirects of fetch requests by module registries.

Also, Molt is designed to be easier to use in development pipelines:

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)

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": {
    "update": "deno run --allow-env --allow-read --allow-net --allow-write=. https://deno.land/x/molt/cli.ts update",
    "update:check": "deno run --allow-env --allow-read --allow-net https://deno.land/x/molt/cli.ts check",
    "update:commit": "deno run --allow-env --allow-read --allow-net --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 <...entrypoints>

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

📝 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.