fix: allow templating of null and undefined in a key path

Germandrummer92 · Germandrummer92 · commit 87febe76ffe9 · 2024-03-05T18:56:23.000+01:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -41,6 +41,7 @@
 - `[jest-config]` Support `testTimeout` in project config ([#14697](https://github.com/jestjs/jest/pull/14697))
 - `[jest-config]` Support `coverageReporters` in project config ([#14697](https://github.com/jestjs/jest/pull/14830))
 - `[jest-config]` Allow `reporters` in project config ([#14768](https://github.com/jestjs/jest/pull/14768))
+- `[jest-each]` Allow `$keypath` templates with null or undefined values ([]())
 - `[@jest/expect-utils]` Fix comparison of `DataView` ([#14408](https://github.com/jestjs/jest/pull/14408))
 - `[@jest/expect-utils]` [**BREAKING**] exclude non-enumerable in object matching ([#14670](https://github.com/jestjs/jest/pull/14670))
 - `[@jest/expect-utils]` Fix comparison of `URL` ([#14672](https://github.com/jestjs/jest/pull/14672))
diff --git a/e2e/each/__tests__/eachTemplate.test.js b/e2e/each/__tests__/eachTemplate.test.js
@@ -0,0 +1,14 @@
+it.each([
+  {something: {nested: 'value'}},
+  {something: null},
+  {something: undefined},
+])('allows templating "$something.nested"', value => {
+  expect(value).toBe(value);
+});
+
+it.each([{array: ['some value']}, {array: null}, {array: undefined}])(
+  'allows templating "$array.length"',
+  value => {
+    expect(value).toBe(value);
+  },
+);
diff --git a/packages/jest-each/src/__tests__/template.test.ts b/packages/jest-each/src/__tests__/template.test.ts
@@ -417,6 +417,30 @@ describe('jest-each', () => {
         );
       });
 
+      test.each([null, undefined])(
+        'calls global with title containing $key.path for %s',
+        value => {
+          const globalTestMocks = getGlobalTestMocks();
+          const eachObject = each.withGlobal(globalTestMocks)`
+          a
+          ${{foo: value}}
+        `;
+          const testFunction = get(eachObject, keyPath);
+          testFunction(
+            'interpolates object keyPath to value: $a.foo.bar',
+            noop,
+          );
+
+          const globalMock = get(globalTestMocks, keyPath);
+          expect(globalMock).toHaveBeenCalledTimes(1);
+          expect(globalMock).toHaveBeenCalledWith(
+            `interpolates object keyPath to value: ${value}`,
+            expectFunction,
+            undefined,
+          );
+        },
+      );
+
       test('calls global with title containing last seen object when $key.path is invalid', () => {
         const globalTestMocks = getGlobalTestMocks();
         const eachObject = each.withGlobal(globalTestMocks)`
diff --git a/packages/jest-each/src/table/interpolation.ts b/packages/jest-each/src/table/interpolation.ts
@@ -71,6 +71,8 @@ export function getPath(
   template: Template,
   [head, ...tail]: Array<string>,
 ): unknown {
+  if (template === null) return 'null';
+  if (template === undefined) return 'undefined';
   if (!head || !Object.prototype.hasOwnProperty.call(template, head))
     return template;
   return getPath(template[head] as Template, tail);
