feat: enforce conventional commit format using convco

flake.nix

@@ -1,6 +1,7 @@
 {
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-22.11";
+    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
     crane.url = "github:ipetkov/crane?rev=98894bb39b03bfb379c5e10523cd61160e1ac782"; # https://github.com/ipetkov/crane/releases/tag/v0.11.0
     crane.inputs.nixpkgs.follows = "nixpkgs";
     flake-utils.url = "github:numtide/flake-utils";
@@ -18,12 +19,17 @@
     };
   };
 
-  outputs = { self, nixpkgs, flake-utils, flake-compat, fenix, crane, advisory-db }:
+  outputs = { self, nixpkgs, nixpkgs-unstable, flake-utils, flake-compat, fenix, crane, advisory-db }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs {
           inherit system;
         };
+
+        pkgs-unstable = import nixpkgs-unstable {
+          inherit system;
+        };
+
         lib = pkgs.lib;
         stdenv = pkgs.stdenv;
 
@@ -885,6 +891,7 @@
                 pkgs.nixpkgs-fmt
                 pkgs.shellcheck
                 pkgs.rnix-lsp
+                pkgs-unstable.convco
                 pkgs.nodePackages.bash-language-server
               ] ++ cliTestsDeps;
               RUST_SRC_PATH = "${fenixChannel.rust-src}/lib/rustlib/src/rust/library";
@@ -950,6 +957,7 @@
                 pkgs.nixpkgs-fmt
                 pkgs.shellcheck
                 pkgs.git
+                pkgs-unstable.convco
               ];
             };
 

misc/git-hooks/commit-msg

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+
+set -eu
+
+export tmp_file="$1.tmp"
+
+function rm_tmp_file {
+  rm -f "$tmp_file"
+}
+
+trap rm_tmp_file EXIT
+
+while : ; do
+  # Sanitize file first, by removing leading lines that are empty or start with a hash,
+  # as `convco` currently does not do it automatically (but git will)
+  echo -n "" > "$tmp_file"
+  body_detected=""
+  while read -r line ; do
+    # skip any initial comments (possibly from previous run)
+    if [ -z "${body_detected:-}" ] && { [[ "$line" =~ ^#.*$ ]] || [ "$line" == "" ]; }; then
+      continue
+    fi
+    body_detected="true"
+
+    echo "$line" >> "$tmp_file"
+  done < "$1"
+
+  # We have a sanitized version in "$tmp_file" now, move it the original
+  cp "$tmp_file" "$1"
+
+
+  # Run convco, start preparing a buffer we will display to the user,
+  # if lint fails.
+  echo -n "# " > "$tmp_file"
+  if convco check < "$1" 2>> "$tmp_file" ; then
+     break
+  fi
+
+  # lint failed, prepare the content to show
+  {
+    echo "# Refer to https://www.conventionalcommits.org/en/v1.0.0/#summary"
+    echo "# Quit without changes to abort"
+    cat "$1"
+  } >> "$tmp_file"
+
+  # "$tmp_file" has a commit message prefixed with comments explaining what's wrong.
+  cp "$tmp_file" "$1"
+  "${VISUAL:-${EDITOR:-vi}}" "$1"
+  if cmp -s "$tmp_file" "$1"; then
+    >&2 echo "Not changes. Exiting..."
+    exit 1
+  fi
+done