erroNotFound option

Author: gajus

README.md

@@ -88,4 +88,5 @@ This will work as you'd expect.
 |Name|Type|Description|Default|
 |---|---|---|---|
 |`allowMultiple`|`Boolean`| Determines whether `className` can have multiple class names. Throws an error when the constrained is not met. |`true`|
-|`includeOriginal`|`Boolean`| Determines whether the original `className` value should be kept in addition to the appended generated value. |`true`|
+|`keepOriginal`|`Boolean`| Determines whether the original `className` value is kept in addition to the appended CSS modules styles CSS class name. |`true`|
+|`errorNotFound`|`Boolean`| Determines whether an error is raised if `className` defines a CSS class(es) that is not present in the CSS modules styles. |`true`|

dist/index.js

@@ -48,6 +48,10 @@ exports['default'] = function (Component, styles) {
                     options.includeOriginal = true;
                 }
 
+                if (options.errorNotFound !== true) {
+                    options.errorNotFound = false;
+                }
+
                 return (0, _linkClass2['default'])(_get(Object.getPrototypeOf(_class.prototype), 'render', this).call(this), styles, options);
             }
         }]);

dist/linkClass.js

@@ -35,12 +35,30 @@ linkClass = function (element) {
         }
 
         newClassName = newClassName.map(function (className) {
-            if (styles[className]) {
-                return className + ' ' + styles[className];
+            if (!styles[className] && options.errorNotFound === true) {
+                throw new Error('"' + className + '" CSS class name is not found in CSS modules styles.');
+            }
+
+            if (options.includeOriginal === false) {
+                if (styles[className]) {
+                    return styles[className];
+                } else {
+                    return '';
+                }
             } else {
-                return className;
+                if (styles[className]) {
+                    return className + ' ' + styles[className];
+                } else {
+                    return className;
+                }
             }
-        }).join(' ');
+        });
+
+        newClassName = newClassName.filter(function (className) {
+            return className.length;
+        });
+
+        newClassName = newClassName.join(' ');
     }
 
     // A child can be either an array, a sole object or a string.

src/index.js

@@ -17,6 +17,10 @@ export default (Component, styles, options = {}) => {
                 options.includeOriginal = true;
             }
 
+            if (options.errorNotFound !== true) {
+                options.errorNotFound = false;
+            }
+
             return linkClass(super.render(), styles, options);
         }
     }

src/linkClass.js

@@ -22,12 +22,30 @@ linkClass = (element, styles = {}, options = {}) => {
         }
 
         newClassName = newClassName.map((className) => {
-            if (styles[className]) {
-                return `${className} ${styles[className]}`;
+            if (!styles[className] && options.errorNotFound === true) {
+                throw new Error(`"${className}" CSS class name is not found in CSS modules styles.`);
+            }
+
+            if (options.includeOriginal === false) {
+                if (styles[className]) {
+                    return styles[className];
+                } else {
+                    return '';
+                }
             } else {
-                return className;
+                if (styles[className]) {
+                    return `${className} ${styles[className]}`;
+                } else {
+                    return className;
+                }
             }
-        }).join(' ');
+        });
+
+        newClassName = newClassName.filter(function (className) {
+            return className.length;
+        });
+
+        newClassName = newClassName.join(' ');
     }
 
     // A child can be either an array, a sole object or a string.

test/linkClass.js

@@ -135,4 +135,22 @@ describe('linkClass', () => {
             });
         });
     });
+
+    describe('when options.includeOriginal is false', () => {
+        it('does not include the original class name', () => {
+            let subject;
+
+            subject = linkClass(<div className='foo bar'></div>, {foo: 'foo-1'}, {includeOriginal: false});
+
+            expect(subject.props.className).to.equal('foo-1');
+        });
+    });
+
+    describe('when options.errorNotFound is true', () => {
+        it('throws an error when className defines a CSS class that does not exist in CSS modules styles', () => {
+            expect(() => {
+                linkClass(<div className='foo'></div>, {}, {errorNotFound: true})
+            }).to.throw(Error, '"foo" CSS class name is not found in CSS modules styles.');
+        });
+    });
 });