nodejs: Add instructions around building and chmod on pre-commit.

specs/nodejs/runner

@@ -49,6 +49,7 @@ cp validate.cjs "$BUILD"/bs.nodejs
 # Explicitly set permissions on all copied files.
 find "$BUILD" -type f -execdir chmod 644 {} +
 find "$BUILD" -type d -execdir chmod 755 {} +
+chmod 755 "$BUILD"/.githooks/pre-commit
 
 # Validate the provided name is usable.
 nix develop "$BUILD" --command bash -c \

specs/nodejs/template/README.md

@@ -9,6 +9,20 @@ run via:
 $ nix develop
 ```
 
+## Building
+
+If you make changes to the `package-lock.json` file, you'll need to update the
+`npmDepsHash` value in `flake.nix`. The easiest way to discover this value is
+by running the following:
+```bash
+$ prefetch-npm-deps package-lock.json
+```
+Alternatively, you can set the value of `npmDepsHash` to `lib.fakeHash` and run:
+```bash
+$ nix build
+```
+Nix will complain with the has value it actually expected.
+
 ## Language Server
 
 The [typescript-language-server](https://github.com/typescript-language-server/typescript-language-server)

specs/nodejs/template/flake.nix

@@ -27,6 +27,7 @@
             version = "0.1.0";
             src = ./.;
             npmDepsHash = "<SHA_256>";
+            # npmDepsHash = pkgs.lib.fakeHash;
 
             # Needed to properly invoke npm run build.
             nativeBuildInputs = [ pkgs.typescript ];