feat(options): implement custom-devshell option

README.md

@@ -9,49 +9,50 @@ Run any command you like in a deterministic [Nix](https://nixos.org/nix/) shell
 Create `.github/workflows/test.yml` in your repo with the following contents:
 
 ```yaml
-name: "Test"
+name: 'Test'
 on:
   pull_request:
   push:
 jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v18
-      with:
-        nix_path: nixpkgs=channel:nixos-unstable
-    - uses: workflow/nix-shell-action@v3
-      with:
-        packages: hello,docker
-        script: |
-          hello
-          docker --help
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v18
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+      - uses: workflow/nix-shell-action@v3
+        with:
+          packages: hello,docker
+          script: |
+            hello
+            docker --help
 ```
 
 You can also pass in environment variables:
 
 ```yaml
-    - uses: workflow/nix-shell-action@v3
-      env:
-        TRANSFORMER: bumblecat
-      with:
-        packages: hello,docker
-        script: |
-          hello $TRANSFORMER
-          docker --help
+- uses: workflow/nix-shell-action@v3
+  env:
+    TRANSFORMER: bumblecat
+  with:
+    packages: hello,docker
+    script: |
+      hello $TRANSFORMER
+      docker --help
 ```
 
 For now, this action implicitly depends on having [Nix] installed and set up correctly, such as through the [install-nix-action] demonstrated in the examples above.
 
 See also [cachix-action](https://github.com/cachix/cachix-action) for a simple binary cache setup to speed up your builds and share binaries with developers.
 
 ## Usage with Flakes
+
 Instead of specifying packages, you can use `flakes` to specify fully qualified flakes to be available in your script.
 This can be used for both local flakes in a `flake.nix` in your repo, as well as external flakes.
 
 ```yaml
-name: "Test"
+name: 'Test'
 on:
   pull_request:
   push:
@@ -76,10 +77,11 @@ jobs:
 ```
 
 ## Flakes from devShell
+
 Instead of specifying `flakes`, you can also tell this action to re-use the `buildInputs` from your `devShell` defined in a `flake.nix`, and automatically make these available to the script:
 
 ```yaml
-name: "Test with Flakes from DevShell"
+name: 'Test with Flakes from DevShell'
 on:
   pull_request:
   push:
@@ -103,41 +105,43 @@ jobs:
 
 ## Options `with: ...`
 
-- `interpreter`:  Interpreter to use in the nix shell shebang, defaults to `bash`. (This is passed to `nix run -c`, used to be `-i` in a nix shell shebang)
+- `interpreter`: Interpreter to use in the nix shell shebang, defaults to `bash`. (This is passed to `nix run -c`, used to be `-i` in a nix shell shebang)
 
 - `packages`: Comma-separated list of packages to pre-install in your shell. Cannot be used together with the `flakes` option.
 
 - `flakes`: Comma-separated list of fully qualified flakes to pre-install in your shell. Use either `packages` or `flakes`. Cannot be used together with the `packages` option.
 
 - `flakes-from-devshell`: If true, supply flakes from a `devShell` provided in your repo's `flake.nix`. You cannot currently combined this with the `flakes` nor `packages` options.
 
+- `custom-devshell`: Specify a custom `devShell` to use. This can be useful if you have a `devShell` that is not named `devShell` in your `flake.nix`. You cannot currently combined this with the `flakes` nor `packages` options.
+
 - `script`: The actual script to execute in your shell. Will be passed to the `interpreter`, which defaults to `bash`
 
 - `working-directory`: Execute the script inside the specified working directory instead of the repository root. Example: `path/to/dir`
 
 ## FAQ: Passing a Github Token against Rate Limits
 
 ```yaml
-name: "Test"
+name: 'Test'
 on:
   pull_request:
   push:
 jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
-    - uses: cachix/install-nix-action@v18
-      with:
-        nix_path: nixpkgs=channel:nixos-unstable
-        extra_nix_config: |
-          access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-    - uses: workflow/nix-shell-action@v3
-      with:
-        packages: hello,docker
-        script: |
-          hello
-          docker --help
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v18
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+          extra_nix_config: |
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+      - uses: workflow/nix-shell-action@v3
+        with:
+          packages: hello,docker
+          script: |
+            hello
+            docker --help
 ```
 
 ---
@@ -146,5 +150,5 @@ jobs:
 
 See https://github.com/actions/typescript-action
 
-[Nix]: https://nixos.org/nix/
+[nix]: https://nixos.org/nix/
 [install-nix-action]: https://github.com/marketplace/actions/install-nix

action.yml

@@ -18,6 +18,10 @@ inputs:
     required: false
     description: 'If set to true, uses devShell instead.'
     default: false
+  custom-devshell:
+    required: false
+    description: 'If set, uses a customly named devShell from the current flake'
+    default: ''
   script:
     required: true
     description: 'The actual script to execute in the shell'

flake.nix

@@ -1,15 +1,20 @@
 {
   description = "A very basic flake";
 
-  outputs = { self, nixpkgs }: {
-
+  outputs = {
+    self,
+    nixpkgs,
+  }: {
     packages.x86_64-linux.hello = nixpkgs.legacyPackages.x86_64-linux.hello;
 
     packages.x86_64-linux.default = self.packages.x86_64-linux.hello;
 
     devShells.x86_64-linux.default = nixpkgs.legacyPackages.x86_64-linux.mkShell {
-      buildInputs = [ nixpkgs.legacyPackages.x86_64-linux.figlet ];
+      buildInputs = [nixpkgs.legacyPackages.x86_64-linux.figlet];
     };
 
+    ci = nixpkgs.legacyPackages.x86_64-linux.mkShell {
+      buildInputs = [nixpkgs.legacyPackages.x86_64-linux.ponysay];
+    };
   };
 }

src/main.ts

@@ -10,6 +10,7 @@ function run(): void {
     const flakesFromDevshell: boolean = core.getBooleanInput(
       'flakes-from-devshell'
     )
+    const customDevshell: string = core.getInput('custom-devshell')
     const script: string = core.getInput('script')
     const workingDirectory: string = core.getInput('working-directory')
 
@@ -33,7 +34,11 @@ function run(): void {
           .map(pkg => `nixpkgs#${pkg.trim()}`)
           .join(' ')
 
-    const nixCommand = flakesFromDevshell ? 'develop' : 'shell'
+    const nixCommand = flakesFromDevshell
+      ? customDevshell
+        ? `develop .#${customDevshell}`
+        : 'develop'
+      : 'shell'
 
     const nixWrapper = `
 set -euo pipefail