feat: show nightly channel in version output

Refs #517

install.sh

@@ -266,6 +266,45 @@ get_installed_version() {
     fi
 }
 
+resolve_install_channel() {
+    case "${MOLE_VERSION:-}" in
+        main | latest)
+            printf 'nightly\n'
+            return 0
+            ;;
+        dev)
+            printf 'dev\n'
+            return 0
+            ;;
+    esac
+
+    if [[ "${MOLE_EDGE_INSTALL:-}" == "true" ]]; then
+        printf 'nightly\n'
+        return 0
+    fi
+
+    printf 'stable\n'
+}
+
+write_install_channel_metadata() {
+    local channel="$1"
+    local metadata_file="$CONFIG_DIR/install_channel"
+
+    local tmp_file
+    tmp_file=$(mktemp "${CONFIG_DIR}/install_channel.XXXXXX") || return 1
+    {
+        printf 'CHANNEL=%s\n' "$channel"
+    } > "$tmp_file" || {
+        rm -f "$tmp_file" 2> /dev/null || true
+        return 1
+    }
+
+    mv -f "$tmp_file" "$metadata_file" || {
+        rm -f "$tmp_file" 2> /dev/null || true
+        return 1
+    }
+}
+
 # CLI parsing (supports main/latest and version tokens).
 parse_args() {
     local -a args=("$@")
@@ -712,6 +751,12 @@ perform_install() {
         installed_version="$source_version"
     fi
 
+    local install_channel
+    install_channel="$(resolve_install_channel)"
+    if ! write_install_channel_metadata "$install_channel"; then
+        log_warning "Could not write install channel metadata"
+    fi
+
     # Edge installs get a suffix to make the version explicit.
     if [[ "${MOLE_EDGE_INSTALL:-}" == "true" ]]; then
         installed_version="${installed_version}-edge"
@@ -795,6 +840,12 @@ perform_update() {
         updated_version="$target_version"
     fi
 
+    local install_channel
+    install_channel="$(resolve_install_channel)"
+    if ! write_install_channel_metadata "$install_channel"; then
+        log_warning "Could not write install channel metadata"
+    fi
+
     echo -e "${GREEN}${ICON_SUCCESS}${NC} Updated to latest version, $updated_version"
 }
 

mole

@@ -87,6 +87,18 @@ is_homebrew_install() {
     return 1
 }
 
+get_install_channel() {
+    local channel_file="$SCRIPT_DIR/install_channel"
+    local channel="stable"
+    if [[ -f "$channel_file" ]]; then
+        channel=$(sed -n 's/^CHANNEL=\(.*\)$/\1/p' "$channel_file" | head -1)
+    fi
+    case "$channel" in
+        nightly | dev | stable) printf '%s\n' "$channel" ;;
+        *) printf 'stable\n' ;;
+    esac
+}
+
 # Background update notice
 check_for_updates() {
     local msg_cache="$HOME/.cache/mole/update_message"
@@ -205,7 +217,13 @@ show_version() {
         install_method="Homebrew"
     fi
 
+    local channel
+    channel=$(get_install_channel)
+
     printf '\nMole version %s\n' "$VERSION"
+    if [[ "$channel" == "nightly" ]]; then
+        printf 'Channel: Nightly\n'
+    fi
     printf 'macOS: %s\n' "$os_ver"
     printf 'Architecture: %s\n' "$arch"
     printf 'Kernel: %s\n' "$kernel"

tests/cli.bats

@@ -14,6 +14,7 @@ setup_file() {
 }
 
 teardown_file() {
+	rm -f "$PROJECT_ROOT/install_channel"
 	rm -rf "$HOME"
 	if [[ -n "${ORIGINAL_HOME:-}" ]]; then
 		export HOME="$ORIGINAL_HOME"
@@ -47,6 +48,7 @@ SCRIPT
 setup() {
 	rm -rf "$HOME/.config"
 	mkdir -p "$HOME"
+	rm -f "$PROJECT_ROOT/install_channel"
 }
 
 @test "mole --help prints command overview" {
@@ -63,6 +65,18 @@ setup() {
 	[[ "$output" == *"$expected_version"* ]]
 }
 
+@test "mole --version shows nightly channel metadata" {
+	expected_version="$(grep '^VERSION=' "$PROJECT_ROOT/mole" | head -1 | sed 's/VERSION=\"\(.*\)\"/\1/')"
+	cat > "$PROJECT_ROOT/install_channel" <<'EOF'
+CHANNEL=nightly
+EOF
+
+	run env HOME="$HOME" "$PROJECT_ROOT/mole" --version
+	[ "$status" -eq 0 ]
+	[[ "$output" == *"Mole version $expected_version"* ]]
+	[[ "$output" == *"Channel: Nightly"* ]]
+}
+
 @test "mole unknown command returns error" {
 	run env HOME="$HOME" "$PROJECT_ROOT/mole" unknown-command
 	[ "$status" -ne 0 ]