Commands Overview

These are useful commands for working with different runtimes (Node.js, and Deno) and managing Deno's caching, modules, and directories.

1. Benchmark runtimes:

   hyperfine "node bench.js" "deno run bench.js" --warmup=100 -i

   This command benchmarks the performance of running the index.js file using Node.js, and Deno. The --warmup=100 flag ensures that each command is warmed up 100 times before measurement, and -i runs the benchmarking interactively.

2. Deno info command:

   deno info "https://docs.deno.com/examples/hello-world.ts"

   This fetches and provides information about the hello-world.ts file from the given URL, including its dependencies and module tree.

3. Deno run with cache reload:

   deno run --reload main.ts

   This runs the main.ts file while forcing a cache reload of the modules to ensure the latest versions are used.

4. Open Deno's cache:

   open ~/Library/Caches/deno/

   Opens the default cache directory on macOS where Deno stores its downloaded modules and files.

5. Create a new Deno directory:

   mkdir deno_dir

   Creates a new directory named deno_dir where you can specify a custom cache location for Deno.

6. Set a custom Deno directory:

   export DENO_DIR=./deno_dir/

   This exports the DENO_DIR environment variable, directing Deno to use the newly created deno_dir as its cache.

7. Cache specific files:

   deno cache main.ts

   Caches the dependencies of the main.ts file for future use, allowing faster execution as it doesn’t have to be downloaded each time.

8. Add a module with Deno:

   deno add jsr/......

   Adds a specific JavaScript or TypeScript module, using Deno's built-in package management capabilities (the full path should replace the jsr/...... part).

9. Use custom Deno cache directory in commands:

   $DENO_DIR
   DENO_DIR=./deno_dir/ deno main.ts

   The first command shows the current value of DENO_DIR, and the second command runs the main.ts file using the deno_dir as the custom cache directory.

10. To install Deno Jupyter, run the following command:

deno jupyter --unstable --install

11. Upgrade to Deno 2.0 Release Candidate:

deno upgrade
deno upgrade rc

References

• JSR Standard Library: An evolving JavaScript/TypeScript standard library repository.
• Deno Third-Party Modules: Official repository for third-party Deno modules.
• Deno Documentation: Deno documentation on TypeScript support and runtime fundamentals.