Add tests for withDefault

Author: jeroenpelgrims

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-dist
+dist
+coverage

README.md

@@ -83,7 +83,7 @@ Currently only a few basic types are supported.
 - `numberParam`: for numbers (integers and floats)
 - `objectParam`: custom Objects that will be serialized to JSON.
 - `booleanParam`: for booleans
-- `dateParam`: for dates
+- `dateParam`: for dates and datetime
 - `arrayParam`: for arrays of the above types  
   NOTE: Nested arrays are currently only possible using `objectParam`. e.g.: `objectParam<number[][]>()`;
 

package.json

@@ -9,7 +9,7 @@
     "prepublish": "npm run build && npm run test",
     "build": "tsup",
     "check": "tsc --noEmit",
-    "test": "jest",
+    "test": "jest --collectCoverage",
     "test:watch": "jest --watch"
   },
   "repository": {

src/core/withDefault.test.ts

@@ -0,0 +1,21 @@
+import { numberParam } from "../converters";
+import { withDefault } from "./withDefault";
+
+describe("withDefault", () => {
+  const { serialize, deserialize } = withDefault(numberParam(), 123);
+
+  test("returns deserialized value when deserializer returns correct value", () => {  
+    expect(deserialize('2')).toBe(2);
+    expect(deserialize('100')).toBe(100);
+    expect(deserialize('-2')).toBe(-2);
+    expect(deserialize('-3.1415')).toBe(-3.1415);
+  });
+
+  test("returns default value when deserializer returns null", () => {
+    expect(deserialize(null)).toBe(123);
+  });
+
+  test("returns default value when deserializer returns undefined", () => {
+    expect(deserialize(undefined as unknown as null)).toBe(123);
+  });
+});