feat(toHaveValue): Enhanced error message with type information… (#219)

* Enhanced error message of toHaveValue

* Added tests

* Refactored tests.

Author: maltebaer

src/__tests__/to-have-value.js

@@ -124,6 +124,26 @@ describe('.toHaveValue', () => {
     `)
   })
 
+  test('throws with type information when the expected text input value has loose equality with received value', () => {
+    const {container} = render(`<input data-testid="one" value="8" />`)
+    const input = container.firstChild
+    let errorMessage
+    try {
+      expect(input).toHaveValue(8)
+    } catch (error) {
+      errorMessage = error.message
+    }
+
+    expect(errorMessage).toMatchInlineSnapshot(`
+      "<dim>expect(</><red>element</><dim>).toHaveValue(</><green>8</><dim>)</>
+
+      Expected the element to have value:
+      <green>  8 (number)</>
+      Received:
+      <red>  8 (string)</>"
+    `)
+  })
+
   test('throws when using not but the expected input value does match', () => {
     const {container} = render(`<input data-testid="one" value="foo" />`)
     const input = container.firstChild

src/to-have-value.js

@@ -21,6 +21,14 @@ export function toHaveValue(htmlElement, expectedValue) {
 
   const receivedValue = getSingleElementValue(htmlElement)
   const expectsValue = expectedValue !== undefined
+
+  let expectedTypedValue = expectedValue
+  let receivedTypedValue = receivedValue
+  if (expectedValue == receivedValue && expectedValue !== receivedValue) {
+    expectedTypedValue = `${expectedValue} (${typeof expectedValue})`
+    receivedTypedValue = `${receivedValue} (${typeof receivedValue})`
+  }
+
   return {
     pass: expectsValue
       ? isEqualWith(receivedValue, expectedValue, compareArraysAsSet)
@@ -35,9 +43,9 @@ export function toHaveValue(htmlElement, expectedValue) {
       return getMessage(
         matcher,
         `Expected the element ${to} have value`,
-        expectsValue ? expectedValue : '(any)',
+        expectsValue ? expectedTypedValue : '(any)',
         'Received',
-        receivedValue,
+        receivedTypedValue,
       )
     },
   }