perf: ⚡️ make postcss-load-config optional for better pkg size

This slims the package 207kbs

BREAKING CHANGE: To load PostCSS config automatically from a file, now it's needed to
manually install "postcss-load-config".

README.md

@@ -29,17 +29,19 @@
 
 ## Installation
 
-`npm install --save-dev svelte-preprocess`
+`npm install -D svelte-preprocess`
 
 The preprocessor module installation is up to the developer.
 
-- `postcss`: `npm install --save-dev postcss`
-- `coffeescript`: `npm install --save-dev coffeescript`
-- `typescript`: `npm install --save-dev typescript`
-- `less`: `npm install --save-dev less`
-- `sass`: `npm install --save-dev node-sass`
-- `pug`: `npm install --save-dev pug`
-- `stylus`: `npm install --save-dev stylus`
+- `postcss`: `npm install -D postcss postcss-load-config`
+- `coffeescript`: `npm install -D coffeescript`
+- `typescript`: `npm install -D typescript`
+- `less`: `npm install -D less`
+- `sass`: `npm install -D node-sass`
+- `pug`: `npm install -D pug`
+- `stylus`: `npm install -D stylus`
+
+_Note: If you want to load your `postcss` configuration from a external file, make sure to also install `postcss-load-config`._
 
 ## Features
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "svelte-preprocess",
-  "version": "2.16.0",
+  "version": "3.0.0",
   "license": "MIT",
   "main": "src/index.js",
   "types": "src/index.d.ts",
@@ -25,7 +25,7 @@
     "test:watch": "jest --no-cache --verbose --watchAll",
     "lint": "eslint \"src/**/*.js\"",
     "format": "prettier --loglevel silent --write \"src/**/*.js\" && eslint --fix \"src/**/*.js\"",
-    "postinstall": "node -e \"console.log('\\u001b[36m\\u001b[1m[svelte-preprocess] Don\\'t forget to install the preprocessors packages that will be used: \\u001b[22m\\u001b[39m\\u001b[34mnode-sass/sass, stylus, less, postcss, coffeescript, pug, etc...\\u001b[0m')\"",
+    "postinstall": "node -e \"console.log('\\u001b[36m\\u001b[1m[svelte-preprocess] Don\\'t forget to install the preprocessors packages that will be used: \\u001b[22m\\u001b[39m\\u001b[34mnode-sass/sass, stylus, less, postcss &  postcss-load-config, coffeescript, pug, etc...\\u001b[0m')\"",
     "version": "npx conventional-changelog-cli -p angular -i CHANGELOG.md -s -r 0 && git add CHANGELOG.md",
     "tag": "git tag -a v$npm_package_version -m 'Release v$npm_package_version'",
     "release": "npm run version && git add package.json && git commit -m \"chore: release v$npm_package_version\"",
@@ -58,6 +58,7 @@
     "node-sass": "^4.12.0",
     "postcss": "^7.0.14",
     "postcss-easy-import": "^3.0.0",
+    "postcss-load-config": "^2.1.0",
     "prettier": "^1.16.4",
     "pug": "^2.0.3",
     "stylus": "^0.54.5",
@@ -70,7 +71,6 @@
   },
   "dependencies": {
     "detect-indent": "^6.0.0",
-    "postcss-load-config": "^2.0.0",
     "strip-indent": "^2.0.0"
   }
 }

src/transformers/postcss.js

@@ -1,5 +1,4 @@
 const postcss = require('postcss')
-const postcssLoadConfig = require(`postcss-load-config`)
 
 const process = async (
   { plugins, parser, syntax },
@@ -37,10 +36,15 @@ module.exports = async ({ content, filename, options, map = undefined }) => {
 
   try {
     /** If not, look for a postcss config file */
+    const postcssLoadConfig = require(`postcss-load-config`)
     options = await postcssLoadConfig(options, options.configFilePath)
   } catch (e) {
     /** Something went wrong, do nothing */
-    console.error(e.message)
+    if (e.code === 'MODULE_NOT_FOUND') {
+      console.error(
+        `[svelte-preprocess] PostCSS configuration was not passed. If you expect to load it from a file, make sure to install "postcss-load-config" and try again ʕ•ᴥ•ʔ`,
+      )
+    }
     return { code: content, map }
   }