Add error message if stack hasn't been defined

Author: philipbordallo

.tape.js

@@ -1,7 +1,6 @@
 module.exports = {
-  'postcss-stack': {
     'basic': {
-      message: 'supports basic usage',
+      message: 'should support basic usage',
       options: {
         list: [
           { beneath: -1 },
@@ -12,7 +11,7 @@ module.exports = {
       }
     },
     'increment': {
-      message: 'allows larger increments',
+      message: 'should allow larger increments',
       options: {
         list: [
           { beneath: -1 },
@@ -24,7 +23,22 @@ module.exports = {
       }
     },
     'reverse': {
-      message: 'allows list to be reversed',
+      message: 'should allow list to be reversed',
+      options: {
+        list: [
+          'modal',
+          'tool-tip',
+          'application',
+          { beneath: -1 }
+        ],
+        reverse: true
+      }
+    },
+    'error-message': {
+      message: 'should throw an error if stack hasn’t been defined',
+      errors: {
+        message: /Unknown/
+      },
       options: {
         list: [
           'modal',
@@ -35,5 +49,4 @@ module.exports = {
         reverse: true
       }
     }
-  }
-};
+  };

package-lock.json

@@ -32,7 +32,7 @@
     "build": "rollup --config config/rollup.config.js --silent",
     "lint": "eslint --config config/eslint.config.js ./src/",
     "pretest": "npm run build && npm run lint",
-    "test": "postcss-tape",
+    "test": "postcss-tape --config=./.tape.js --plugin=./dist/index.cjs.js",
     "version": "auto-changelog -p && git add CHANGELOG.md"
   },
   "dependencies": {
@@ -45,7 +45,7 @@
     "@philipbordallo/eslint-config": "^2.1.0",
     "auto-changelog": "^1.8.0",
     "eslint": "^5.6.1",
-    "postcss-tape": "^2.2.0",
+    "postcss-tape": "^3.0.0-rc.2",
     "rollup": "^0.66.2",
     "rollup-plugin-babel": "^4.0.3"
   }

package.json

@@ -3,10 +3,10 @@ import parser from 'postcss-values-parser';
 
 import getStack from './lib/getStack';
 
-
+const PLUGIN_NAME = 'postcss-stack';
 const stackRegExp = /(^|[^\w-])(stack?)\(/i;
 
-export default postcss.plugin('postcss-stack', options => (root) => {
+export default postcss.plugin(PLUGIN_NAME, options => (root) => {
   const stacked = getStack(options);
 
   root.walkDecls((decl) => {
@@ -18,7 +18,15 @@ export default postcss.plugin('postcss-stack', options => (root) => {
       ast.walkType('func', (node) => {
         const stack = node.nodes.filter(item => item.type === 'string')[0].value;
 
-        node.replaceWith(stacked[stack]);
+        if (typeof stacked[stack] !== 'undefined') {
+          node.replaceWith(stacked[stack]);
+        }
+        else {
+          throw decl.error('Unknown stack', {
+            plugin: PLUGIN_NAME,
+            word: stack,
+          });
+        }
       });
 
       const modifiedValue = ast.toString();

src/index.js

@@ -0,0 +1,3 @@
+.modal {
+  z-index: stack('does-not-exist')
+}