Expose two templates: default and example (#69)

Co-authored-by: Sridhar Ratnakumar <srid@srid.ca>

.github/workflows/ci.yaml

@@ -14,17 +14,30 @@ jobs:
           extra_nix_config: |
             experimental-features = nix-command flakes
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-      - name: Test template
+      - name: Test flake templates
         id: template
         run: |
           FLAKE=$(pwd)
           TEMP_DIR=$(mktemp -d)
           cd $TEMP_DIR
+
+          function templateTest () {
+            # Build haskell executable
+            nix build --override-input haskell-flake path:${FLAKE}
+            # Test haskell devshell (via HLS check)
+            nix develop --override-input haskell-flake path:${FLAKE} -c haskell-language-server
+          }
+
+          set -x
+          #### Test "#example" template
+          nix flake init -t $FLAKE#example
+          templateTest
+
+          ### Test "#default" template
+          rm -f flake.nix
           nix flake init -t $FLAKE
-          # Build haskell executable
-          nix build --override-input haskell-flake path:${FLAKE}
-          # Test haskell devshell (via HLS check)
-          nix develop --override-input haskell-flake path:${FLAKE} -c haskell-language-server
+          templateTest
+
       - name: Run test
         id: test
         run: ./runtest.sh

CHANGELOG.md

@@ -5,6 +5,7 @@
 - New features
   - #63: Add `config.haskellProjects.${name}.outputs` containing all flake outputs for that project.
   - #49: The `packages` option now autodiscovers the top-level `.cabal` file as its default value.
+  - #69: The default flake template creates `flake.nix` only, while the `#example` one creates the full Haskell project template.
 - API changes
     - #37: Group `buildTools` (renamed to `tools`), `hlsCheck` and `hlintCheck` under the `devShell` submodule option; and allow disabling them all using `devShell.enable = false;` (useful if you want haskell-flake to produce just the package outputs).
     - #64: Remove hlintCheck (use [treefmt-nix](https://github.com/numtide/treefmt-nix#flake-parts) instead)

README.md

@@ -8,17 +8,21 @@ To keep `flake.nix` smaller (see examples below) and declarative ([what](https:/
 
 ## Usage
 
-To use `haskell-flake` in your Haskell projects, run:
+To use `haskell-flake` in your *existing* Haskell projects, run:
 
 ``` nix
 nix flake init -t github:srid/haskell-flake
 ```
 
-This will generate a template Haskell project with a `flake.nix`. If you already have a Haskell project, copy over this `flake.nix` and adjust accordingly.
+To create a *new* Haskell project, run:
+
+``` nix
+nix flake init -t github:srid/haskell-flake#example
+```
 
 ### Template
 
-If you are bootstrapping a *new* Haskell project, you may use https://github.com/srid/haskell-template which already uses `haskell-flake` along with other opinionated defaults.
+You may also use https://github.com/srid/haskell-template which already uses `haskell-flake` along with other opinionated defaults.
 
 ## Documentation
 

flake.nix

@@ -3,7 +3,11 @@
   outputs = { self, ... }: {
     flakeModule = ./flake-module.nix;
     templates.default = {
-      description = "Example project using haskell-flake";
+      description = "A simple flake.nix using haskell-flake";
+      path = builtins.path { path = ./example; filter = path: _: baseNameOf path == "flake.nix"; };
+    };
+    templates.example = {
+      description = "Example Haskell project using haskell-flake";
       path = ./example;
     };
   };