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deno_run

A project manifest definition and runner for Deno.

Usage

Install using deno to bootstrap deno_run:

deno install --allow-run https://deno.land/x/deno_run/deno_run.ts bootstrap

Then, projects which implement DenoManifest as manifest.ts can be run or installed using deno_run:

# Runs a project manifest.
deno_run https://deno.land/x/some_project/manifest.ts

# Installs
deno_run install https://deno.land/x/some_project/manifest.ts

# Upgrades
deno_run upgrade https://deno.land/x/some_project/manifest.ts

The user will be prompted to accept permissions from the manifest, with a clear, human-readable explanation of each requested permission.

For more details, run deno_run help.

manifest.ts

The metadata for a Deno project which supports this tool can be found in a file named manifest.ts in the project root. It is a plain TypeScript file which exports either a default or a named manifest object. The export object must conform to both the DenoManifest interface and the DenoManifestSchema JSON schema; these can be found in types.ts. The manifest will be imported in a sandbox environment which disallows any privileged API and which strips the export of any non-primitive, non-object, non-array value.

An easy check-list for manifest.ts:

  • No use of import
  • No use of Deno, window, etc.
  • Does not export functions, classes, etc.

That’s it, although a validate command is also offered. Using TypeScript to describe the metadata should come naturally in the context of Deno, and it should allow more complex composing of metadata since its code will be executed on import.

The manifest will then be used to construct the arguments for the project’s entry module, whether installing or running using deno_run.

Why

Not all projects are intended as modules; some (including this very one) are command line tools. End users should not have to worry about excessively long or descriptive commands in order to run or install command line tools. However, it should be possible to present users with the required permissions for a particular tool or project, and it should be possible to reason about a project’s metadata.

There are multiple issues which discuss an equivalent to package.json or a permissions file:

Many of these discussions include a lot of talk about Node.js doing things a certain way, and well, people are just used to it. I completely disagree; Deno is trying to accomplish something very intentional in breaking away from that ecosystem. Security, composability, and ease of use are all a part of the forward-path for Deno, as well as more that’s not yet well-defined or yet well-understood. The author of deno_run is opinionated that Deno is the proper place for package management and tooling; the manifest file is not for every Deno project but is instead meant to remove friction where it concerns running and installing Deno projects which are command line tools.