Introduce %$ option to add number of the test to its title

CHANGELOG.md

@@ -29,6 +29,7 @@
 - `[jest-snapshot]` [**BREAKING**] Add support for [Error causes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause) in snapshots ([#13965](https://github.com/facebook/jest/pull/13965))
 - `[jest-snapshot]` Support Prettier 3 ([#14566](https://github.com/facebook/jest/pull/14566))
 - `[pretty-format]` [**BREAKING**] Do not render empty string children (`''`) in React plugin ([#14470](https://github.com/facebook/jest/pull/14470))
+- `[jest-each]` Introduce `%$` option to add number of the test to its title ([#14710](https://github.com/jestjs/jest/pull/14710))
 
 ### Fixes
 

docs/GlobalAPI.md

@@ -248,6 +248,7 @@ Use `describe.each` if you keep duplicating the same test suites with different
     - `%j` - JSON.
     - `%o` - Object.
     - `%#` - Index of the test case.
+    - `%$` - Number of the test case.
     - `%%` - single percent sign ('%'). This does not consume an argument.
   - Or generate unique test titles by injecting properties of test case object with `$variable`
     - To inject nested object values use you can supply a keyPath i.e. `$variable.path.to.value`
@@ -550,6 +551,7 @@ Use `test.concurrent.each` if you keep duplicating the same test with different
     - `%j` - JSON.
     - `%o` - Object.
     - `%#` - Index of the test case.
+    - `%$` - Number of the test case.
     - `%%` - single percent sign ('%'). This does not consume an argument.
 - `fn`: `Function` the test to be run, this is the function that will receive the parameters in each row as function arguments, **this will have to be an asynchronous function**.
 - Optionally, you can provide a `timeout` (in milliseconds) for specifying how long to wait for each row before aborting. The default timeout is 5 seconds.
@@ -692,6 +694,7 @@ Use `test.each` if you keep duplicating the same test with different data. `test
     - `%j` - JSON.
     - `%o` - Object.
     - `%#` - Index of the test case.
+    - `%$` - Number of the test case.
     - `%%` - single percent sign ('%'). This does not consume an argument.
   - Or generate unique test titles by injecting properties of test case object with `$variable`
     - To inject nested object values use you can supply a keyPath i.e. `$variable.path.to.value`

packages/jest-each/README.md

@@ -40,6 +40,7 @@ jest-each allows you to provide multiple arguments to your `test`/`describe` whi
   - `%j` - JSON.
   - `%o` - Object.
   - `%#` - Index of the test case.
+  - `%$` - Number of the test case.
   - `%%` - single percent sign ('%'). This does not consume an argument.
 - Unique test titles by injecting properties of test case object
 - 🖖 Spock like data tables with [Tagged Template Literals](#tagged-template-literal-of-rows)
@@ -118,6 +119,7 @@ const each = require('jest-each').default;
     - `%j` - JSON.
     - `%o` - Object.
     - `%#` - Index of the test case.
+    - `%$` - Number of the test case.
     - `%%` - single percent sign ('%'). This does not consume an argument.
   - Or generate unique test titles by injecting properties of test case object with `$variable`
     - To inject nested object values use you can supply a keyPath i.e. `$variable.path.to.value`
@@ -144,6 +146,7 @@ const each = require('jest-each').default;
     - `%j` - JSON.
     - `%o` - Object.
     - `%#` - Index of the test case.
+    - `%$` - Number of the test case.
     - `%%` - single percent sign ('%'). This does not consume an argument.
   - Or generate unique test titles by injecting properties of test case object with `$variable`
     - To inject nested object values use you can supply a keyPath i.e. `$variable.path.to.value`

packages/jest-each/src/__tests__/array.test.ts

@@ -144,7 +144,7 @@ describe('jest-each', () => {
         ]);
         const testFunction = get(eachObject, keyPath);
         testFunction(
-          'expected string: %% %%s %s %d %s %s %d %j %s %j %d %d %#',
+          'expected string: %% %%s %s %d %s %s %d %j %s %j %d %d %# %$',
           noop,
         );
 
@@ -153,14 +153,14 @@ describe('jest-each', () => {
         expect(globalMock).toHaveBeenCalledWith(
           `expected string: % %s hello 1 null undefined 1.2 ${JSON.stringify({
             foo: 'bar',
-          })} () => {} [] Infinity NaN 0`,
+          })} () => {} [] Infinity NaN 0 1`,
           expectFunction,
           undefined,
         );
         expect(globalMock).toHaveBeenCalledWith(
           `expected string: % %s world 1 null undefined 1.2 ${JSON.stringify({
             baz: 'qux',
-          })} () => {} [] Infinity NaN 1`,
+          })} () => {} [] Infinity NaN 1 2`,
           expectFunction,
           undefined,
         );

packages/jest-each/src/table/array.ts

@@ -15,6 +15,7 @@ import {type Templates, interpolateVariables} from './interpolation';
 const SUPPORTED_PLACEHOLDERS = /%[#Odfijops]/g;
 const PRETTY_PLACEHOLDER = '%p';
 const INDEX_PLACEHOLDER = '%#';
+const NUMBER_PLACEHOLDER = '%$';
 const PLACEHOLDER_PREFIX = '%';
 const ESCAPED_PLACEHOLDER_PREFIX = /%%/g;
 const JEST_EACH_PLACEHOLDER_ESCAPE = '@@__JEST_EACH_PLACEHOLDER_ESCAPE__@@';
@@ -71,7 +72,10 @@ const formatTitle = (
 
         return util.format(formattedTitle, normalisedValue);
       },
-      interpolateTitleIndex(interpolateEscapedPlaceholders(title), rowIndex),
+      interpolateTitleIndexAndNumber(
+        interpolateEscapedPlaceholders(title),
+        rowIndex,
+      ),
     )
     .replaceAll(
       new RegExp(JEST_EACH_PLACEHOLDER_ESCAPE, 'g'),
@@ -92,8 +96,10 @@ const getMatchingPlaceholders = (title: string) =>
 const interpolateEscapedPlaceholders = (title: string) =>
   title.replaceAll(ESCAPED_PLACEHOLDER_PREFIX, JEST_EACH_PLACEHOLDER_ESCAPE);
 
-const interpolateTitleIndex = (title: string, index: number) =>
-  title.replace(INDEX_PLACEHOLDER, index.toString());
+const interpolateTitleIndexAndNumber = (title: string, index: number) =>
+  title
+    .replace(INDEX_PLACEHOLDER, index.toString())
+    .replace(NUMBER_PLACEHOLDER, (index + 1).toString());
 
 const interpolatePrettyPlaceholder = (title: string, value: unknown) =>
   title.replace(PRETTY_PLACEHOLDER, pretty(value, {maxDepth: 1, min: true}));