Expand upon and add coverage for throws on invalid export type

Author: dhharker

__tests__/index.spec.js

@@ -23,7 +23,6 @@ describe('js-to-styles-vars-loader', () => {
             spyOn(operator, 'getResource').and.callThrough();
             loader.call(context, 'asdf');
             expect(operator.getResource).toHaveBeenCalledWith(context);
-
         });
 
         it('calls getPreprocessorType with resource', () => {
@@ -54,7 +53,23 @@ describe('js-to-styles-vars-loader', () => {
         });
     });
 
-
+    describe('guardExportType', () => {
+      it ("throws on anything except an object, does not throw otherwise", () => {
+        const areOk = [{}, {a: "foo"}];
+        const areNotOk = [[], ["a"], "", "123", 123, false, true];
+        expect(() => {
+            for (const okThing of areOk) {
+                operator.guardExportType(okThing, "");
+            }
+        }).not.toThrow();
+        for (const okThing of areNotOk) {
+            expect(() => {
+                operator.guardExportType(okThing, "");
+            }).toThrow();
+        }
+
+      })
+    });
 
     describe('getVarData', () => {
         const context = {
@@ -75,6 +90,51 @@ describe('js-to-styles-vars-loader', () => {
             const varData = operator.getVarData(path.join(context.context, './mocks/corners.js'), 'deep.nested');
             expect(varData).toEqual({ color: '#f00'});
         });
+
+        it('throws on an missing module', () => {
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/this_is_not_an_existing_file.js'));
+            }).toThrow();
+        })
+        it('throws on a non-object export', () => {
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/null_export.js'));
+            }).toThrow();
+        })
+
+
+
+        it('throws on an empty property', () => {
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'empty');
+            }).toThrow();
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'notEmptyObject');
+            }).not.toThrow();
+        })
+
+        it('does not throw on an empty object', () => {
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'emptyObject');
+            }).not.toThrow();
+        })
+
+        it('throws on a non-object property', () => {
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'falsey');
+            }).toThrow();
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'truthy');
+            }).toThrow();
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'emptyArray');
+            }).toThrow();
+            expect(() => {
+                operator.getVarData(path.join(context.context, './mocks/bad_exports.js'), 'nonEmptyArray');
+            }).toThrow();
+
+        })
+
     });
 
     describe('transformToSassVars', () => {

index.js

@@ -6,17 +6,22 @@ const requireReg = /require\s*\((["'])([\w.\/]+)(?:\1)\)((?:\.[\w_-]+)*);?/igm;
 
 const operator = {
 
+    guardExportType (data, relativePath) {
+        if (typeof data !== "object" || Array.isArray(data)) {
+            throw new Error(`Value must be an object '${relativePath}'`)
+        }
+    },
+
     getVarData (relativePath, property) {
         const data = require(relativePath);
         decache(relativePath);
         if (!data) {
             throw new Error(`No data in '${relativePath}'`)
+            this.guardExportType(data, relativePath);
         }
         if (property) {
             const propVal = squba(data, property);
-            if (!propVal) {
-                throw new Error(`Empty property: 'require("${relativePath}")${property}`);
-            }
+            this.guardExportType(propVal, relativePath);
             return propVal;
         }
         return data;