feat: allow array element for test.each/for title formatting (#7522)

Author: hi-ogawa

docs/api/index.md

@@ -331,16 +331,29 @@ test.each([
 // ✓ add(2, 1) -> 3
 ```
 
-You can also access object properties with `$` prefix, if you are using objects as arguments:
+You can also access object properties and array elements with `$` prefix:
 
-  ```ts
-  test.each([
-    { a: 1, b: 1, expected: 2 },
-    { a: 1, b: 2, expected: 3 },
-    { a: 2, b: 1, expected: 3 },
-  ])('add($a, $b) -> $expected', ({ a, b, expected }) => {
-    expect(a + b).toBe(expected)
-  })
+```ts
+test.each([
+  { a: 1, b: 1, expected: 2 },
+  { a: 1, b: 2, expected: 3 },
+  { a: 2, b: 1, expected: 3 },
+])('add($a, $b) -> $expected', ({ a, b, expected }) => {
+  expect(a + b).toBe(expected)
+})
+
+// this will return
+// ✓ add(1, 1) -> 2
+// ✓ add(1, 2) -> 3
+// ✓ add(2, 1) -> 3
+
+test.each([
+  [1, 1, 2],
+  [1, 2, 3],
+  [2, 1, 3],
+])('add($0, $1) -> $2', (a, b, expected) => {
+  expect(a + b).toBe(expected)
+})
 
 // this will return
 // ✓ add(1, 1) -> 2

packages/runner/src/suite.ts

@@ -816,16 +816,21 @@ function formatTitle(template: string, items: any[], idx: number) {
   }
 
   let formatted = format(template, ...items.slice(0, count))
-  if (isObject(items[0])) {
-    formatted = formatted.replace(
-      /\$([$\w.]+)/g,
-      // https://github.com/chaijs/chai/pull/1490
-      (_, key) =>
-        objDisplay(objectAttr(items[0], key), {
-          truncate: runner?.config?.chaiConfig?.truncateThreshold,
-        }) as unknown as string,
-    )
-  }
+  const isObjectItem = isObject(items[0])
+  formatted = formatted.replace(
+    /\$([$\w.]+)/g,
+    (_, key: string) => {
+      const isArrayKey = /^\d+$/.test(key)
+      if (!isObjectItem && !isArrayKey) {
+        return `$${key}`
+      }
+      const arrayElement = isArrayKey ? objectAttr(items, key) : undefined
+      const value = isObjectItem ? objectAttr(items[0], key, arrayElement) : arrayElement
+      return objDisplay(value, {
+        truncate: runner?.config?.chaiConfig?.truncateThreshold,
+      }) as unknown as string
+    },
+  )
   return formatted
 }
 

test/reporters/fixtures/test-for-title.test.ts

@@ -0,0 +1,50 @@
+import { expect, test } from "vitest"
+
+test.for([
+  { 0: 'a', 1: {}, 2: { te: "st" } },
+  { "0": 'b', "1": [], "2": ["test"] },
+])('test.for object : 0 = $0, 2 = $2', () => {});
+
+test.each([
+  { 0: 'a', 1: {}, 2: { te: "st" } },
+  { "0": 'b', "1": [], "2": ["test"] },
+])('test.each object : 0 = $0, 2 = $2 ', () => {});
+
+test.for([
+  ['a', {}, { te: "st" }],
+  ['b', [], [ "test" ]],
+])('test.for array : 0 = $0, 2 = $2', () => {});
+
+test.each([
+  ['a', {}, { te: "st" }],
+  ['b', [], [ "test" ]],
+])('test.each array : 0 = $0, 2 = $2', () => {});
+
+test.each([
+  { a: 1, b: 1, expected: 2 },
+  { a: 1, b: 2, expected: 3 },
+  { a: 2, b: 1, expected: 3 },
+])('object : add($a, $b) -> $expected', ({ a, b, expected }) => {
+  expect(a + b).toBe(expected)
+})
+
+test.each([
+  [1, 1, 2],
+  [1, 2, 3],
+  [2, 1, 3],
+])('array : add($0, $1) -> $2', (a, b, expected) => {
+  expect(a + b).toBe(expected)
+})
+
+test.for([
+  [{ k1: "v1" }, { k2: "v2" }],
+])('first array element is object: 0 = $0, 1 = $1, k1 = $k1, k2 = $k2', () => {})
+
+test.for([
+  ["foo", "bar"],
+])('first array element is not object: 0 = $0, 1 = $1, k = $k', () => {})
+
+test.for([
+  { k: "v1" },
+  { k: "v2" },
+])('not array: 0 = $0, 1 = $1, k = $k', () => {})

test/reporters/tests/default.test.ts

@@ -189,6 +189,38 @@ describe('default reporter', async () => {
     expect(stdout).toContain('✓ passed > 1-based index of the test case is 2')
     expect(stdout).toContain('✓ passed > 1-based index of the test case is 3')
   })
+
+  test('test.each/for title format', async () => {
+    const { stdout } = await runVitest({
+      include: ['fixtures/test-for-title.test.ts'],
+      reporters: [['default', { isTTY: true, summary: false }]],
+      config: false,
+    })
+    expect(
+      [...stdout.matchAll(/(✓ .*)$/gm)].map(v => v[0]).filter(v => !v.includes('ms')),
+    ).toMatchInlineSnapshot(`
+      [
+        "✓ test.for object : 0 = 'a', 2 = { te: 'st' }",
+        "✓ test.for object : 0 = 'b', 2 = [ 'test' ]",
+        "✓ test.each object : 0 = 'a', 2 = { te: 'st' } ",
+        "✓ test.each object : 0 = 'b', 2 = [ 'test' ] ",
+        "✓ test.for array : 0 = 'a', 2 = { te: 'st' }",
+        "✓ test.for array : 0 = 'b', 2 = [ 'test' ]",
+        "✓ test.each array : 0 = 'a', 2 = { te: 'st' }",
+        "✓ test.each array : 0 = 'b', 2 = [ 'test' ]",
+        "✓ object : add(1, 1) -> 2",
+        "✓ object : add(1, 2) -> 3",
+        "✓ object : add(2, 1) -> 3",
+        "✓ array : add(1, 1) -> 2",
+        "✓ array : add(1, 2) -> 3",
+        "✓ array : add(2, 1) -> 3",
+        "✓ first array element is object: 0 = { k1: 'v1' }, 1 = { k2: 'v2' }, k1 = 'v1', k2 = undefined",
+        "✓ first array element is not object: 0 = 'foo', 1 = 'bar', k = $k",
+        "✓ not array: 0 = { k: 'v1' }, 1 = undefined, k = 'v1'",
+        "✓ not array: 0 = { k: 'v2' }, 1 = undefined, k = 'v2'",
+      ]
+    `)
+  })
 }, 120000)
 
 function trimReporterOutput(report: string) {