chore: support .env template at root (#2255)

A utility that copies the .env settings from a user's root to the project to ease the following workflow:

git clean -dfx
yarn install

Checking out a clean repo is a critical part of the workflow but in doing so, it removes any uncommitted utilities such as the .env file with the Chromatic project token. Any time a yarn install is run, this utility script tries to copy variables listed in the example file from root.

Author: castastrophe

.env.example

@@ -0,0 +1,15 @@
+CHROMATIC_PROJECT_TOKEN=1234abcd
+
+# NX settings
+NX_PREFER_TS_NODE=true
+NX_INTERACTIVE=true
+
+# Default dev environment settings
+NODE_ENV=development
+STORYBOOK_URL="/preview/"
+WATCH_MODE=true
+
+# Optional NX settings
+NX_VERBOSE_LOGGING=false
+NX_SKIP_NX_CACHE=false
+NX_PERF_LOGGING=false

package.json

@@ -45,8 +45,9 @@
     "mv:preview": "rimraf dist/preview && mv tools/preview/storybook-static dist/preview",
     "new": "nx run @spectrum-css/generator:new",
     "precommit": "lint-staged",
-    "prepare": "husky install && yarn migration:clean",
+    "prepare": "husky install && run-p refresh:env migration:clean",
     "prepare:site": "run-s clean:docs build:all",
+    "refresh:env": "test -n \"${BASH_VERSION}\" && bash ./tasks/copy-env-from-root.sh || exit 0",
     "prerelease": "yarn version:build",
     "release": "lerna publish",
     "release:beta-from-package": "yarn release from-package --conventional-prerelease --preid beta --pre-dist-tag beta --no-private",

tasks/copy-env-from-root.sh

@@ -0,0 +1,76 @@
+#!/usr/bin/bash
+
+# Copyright 2023 Adobe. All rights reserved.
+# This file is licensed to you under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License. You may obtain a copy
+# of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software distributed under
+# the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+# OF ANY KIND, either express or implied. See the License for the specific language
+# governing permissions and limitations under the License.
+
+copy_env_file() {
+    # Check if an input was provided
+    [[ -z "$1" ]] && return
+
+    example=$1/.env.example
+
+    # Validate that the file exists
+    [[ ! -f "$example" ]] && return
+
+    # Create the local .env file if it doesn't exist
+    [[ ! -f "$1/.env" ]] && touch $1/.env
+
+    # Read in the local env example, line-by-line and look for variable names
+    while IFS= read -r example_line; do
+        if [[ "$example_line" = "#"* || "$example_line" = "" ]]; then
+            echo "${example_line}" >> .env
+            continue
+        fi
+
+        if [[ "$example_line" != *"="* ]]; then
+            continue
+        fi
+
+        # Split the line into an array with 0=key, 1=value
+        while IFS='=' read -ra example_var; do
+
+            if [[ "${example_var[0]}" = "" || "${example_var[1]}" = "" ]]; then
+                continue
+            fi
+
+            # If the variable does not exist in the home .env file, write it to the local .env file as-is
+            if [[ -z $(grep "${example_var[0]}=" $HOME/.env) ]]; then
+                echo "${example_var[0]}=${example_var[1]}" >> .env
+                continue
+            fi
+
+            if ! test -f $HOME/.env; then
+                continue
+            fi
+
+            # Look for that variable name in the root .env file
+            while IFS= read -r root_line; do
+                while IFS='=' read -ra root_var; do
+                    if [[ "${root_var[0]}" = "${example_var[0]}" ]]; then
+                        # Write the variable to the local .env file
+                        echo "${example_var[0]}=${root_var[1]}" >> .env
+                        continue
+                    fi
+                done <<< "$root_line"
+            done < <(grep -v '^#' $HOME/.env)
+        done <<< "$example_line"
+    done < $example
+}
+
+# Check the directory for an .env.example file (confirm first that we're not inside a node_modules folder)
+for example in $(find . -path \*.env.example -not -path \*/node_modules/\* -exec dirname {} \;); do
+    # If the directory does not already have an .env file, copy relevant values from the user's root .env
+    if [[ -f "$example/.env" ]]; then
+        exit 0
+    else
+        echo "🪄 Using .env.example to generate a local .env"
+        copy_env_file $example
+    fi
+done