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🦕 Molt

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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 = await FileUpdate.collect(updates);
await 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.ts";

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

await 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 tool is also provided as cli.ts for convenience or a reference implementation, which is supposed to cover most of the use cases.

Installation (optional)

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

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

Alternatively, you may prefer to run the remote script directly through deno task for reproducibility:

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

Usage

Update dependencies interactively

The most interactive interface is provided as check sub-command of cli.ts. Run molt check --help for more details.

deno run --allow-env --allow-read --allow-net --allow-write=. --allow-run\
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 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
  test/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

💾 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
? Tasks to run before each commit (comma separated) › lock, test
? Tasks to run after each commit (comma separated) › 

- 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. Run molt update --help for more details.

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,deno\
https://deno.land/x/molt/cli.ts update --commit --pre-commit=check,test <...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.

References

Molt is inspired by prior works such as

and of full respect to the authors.