refactor: rework info generation

Makefile

@@ -1,5 +1,6 @@
 VERSION := 1.0.0
 BUILD_INFO_FILE := Sources/BuildInfo.swift
+BUILD_INFO_TEMPLATE := Sources/BuildInfo.template.swift
 
 .PHONY: help
 help: ## print this message
@@ -11,7 +12,8 @@ help: ## print this message
 
 .PHONY: generate
 generate: ## generate build info
-	@bash scripts/generate.bash $(VERSION)
+	@bash build/generate-info.sh \
+		"${BUILD_INFO_TEMPLATE}" "${VERSION}" > "${BUILD_INFO_FILE}"
 
 .PHONY: build
 build: generate ## build runon

Package.swift

@@ -26,7 +26,7 @@ let package = Package(
                 .product(name: "Rainbow", package: "Rainbow"),
                 .product(name: "Shellac", package: "swift-shellac"),
             ],
-			exclude: ["BuildInfo.swift.dist"]
+			exclude: ["BuildInfo.template.swift"]
         ),
         .testTarget(
             name: "runonTests",

Sources/BuildInfo.swift.dist → Sources/BuildInfo.template.swift

@@ -1,4 +1,4 @@
 // This file is autogenerated. Do not edit it by hand.
 let kAppVersion = "$APP_VERSION"
-let kBuildCommit = "$BUILD_COMMIT"
-let kBuildDate = "$BUILD_DATE"
+let kBuildCommit = "$APP_BUILD_COMMIT"
+let kBuildDate = "$APP_BUILD_DATE"

build/generate-info.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+# Generate info file from template
+# Usage: ./generate-info.sh <build-info-template> <version>
+# Supported template variables:
+# - $APP_VERSION - app version
+# - $APP_BUILD_COMMIT - current commit hash
+# - $APP_BUILD_DATE - current build date
+
+set -e
+
+if [ -z "$1" ] || [ -z "$2" ]; then
+	echo "Usage: $0 <build-info-template> <version>"
+	exit 1
+fi
+
+TEMPLATE_PATH="$1"
+VERSION="$2"
+
+APP_VERSION="$VERSION" \
+APP_BUILD_COMMIT="$(git rev-parse --short HEAD)" \
+APP_BUILD_DATE="$(date -u +"%Y-%m-%d")" \
+	envsubst "\
+		\$APP_VERSION \
+		\$APP_BUILD_COMMIT \
+		\$APP_BUILD_DATE" \
+		< "$TEMPLATE_PATH"