feat(coverage): autoUpdate to support percentage formatting

docs/config/index.md

@@ -1450,14 +1450,31 @@ Check thresholds per file.
 
 ##### coverage.thresholds.autoUpdate
 
-- **Type:** `boolean`
+- **Type:** `boolean | function`
 - **Default:** `false`
 - **Available for providers:** `'v8' | 'istanbul'`
 - **CLI:** `--coverage.thresholds.autoUpdate=<boolean>`
 
 Update all threshold values `lines`, `functions`, `branches` and `statements` to configuration file when current coverage is better than the configured thresholds.
 This option helps to maintain thresholds when coverage is improved.
 
+You can also pass a function for formatting the updated threshold values:
+
+<!-- eslint-skip -->
+```ts
+{
+  coverage: {
+    thresholds: {
+      // Update thresholds without decimals
+      autoUpdate: (newThreshold) => Math.floor(newThreshold),
+
+      // 95.85 -> 95
+      functions: 95,
+    }
+  }
+}
+```
+
 ##### coverage.thresholds.100
 
 - **Type:** `boolean`

docs/guide/cli-generated.md

@@ -191,7 +191,7 @@ Check thresholds per file. See `--coverage.thresholds.lines`, `--coverage.thresh
 
 ### coverage.thresholds.autoUpdate
 
-- **CLI:** `--coverage.thresholds.autoUpdate`
+- **CLI:** `--coverage.thresholds.autoUpdate <boolean|function>`
 - **Config:** [coverage.thresholds.autoUpdate](/config/#coverage-thresholds-autoupdate)
 
 Update threshold values: "lines", "functions", "branches" and "statements" to configuration file when current coverage is above the configured thresholds (default: `false`)

packages/vitest/src/node/cli/cli-config.ts

@@ -254,6 +254,17 @@ export const cliOptionsConfig: VitestCLIOptions = {
           autoUpdate: {
             description:
               'Update threshold values: "lines", "functions", "branches" and "statements" to configuration file when current coverage is above the configured thresholds (default: `false`)',
+            argument: '<boolean|function>',
+            subcommands: null,
+            transform(value) {
+              if (value === 'true' || value === 'yes' || value === true) {
+                return true
+              }
+              if (value === 'false' || value === 'no' || value === false) {
+                return false
+              }
+              return value
+            },
           },
           lines: {
             description:

packages/vitest/src/node/coverage.ts

@@ -578,13 +578,16 @@ export class BaseCoverageProvider<Options extends ResolvedCoverageOptions<'istan
 
       updatedThresholds = true
 
+      const thresholdFormatter = typeof this.options.thresholds?.autoUpdate === 'function' ? this.options.thresholds?.autoUpdate : (value: number) => value
+
       for (const [threshold, newValue] of thresholdsToUpdate) {
+        const formattedValue = thresholdFormatter(newValue)
         if (name === GLOBAL_THRESHOLDS_KEY) {
-          config.test.coverage.thresholds[threshold] = newValue
+          config.test.coverage.thresholds[threshold] = formattedValue
         }
         else {
           const glob = config.test.coverage.thresholds[name as Threshold] as ResolvedThreshold['thresholds']
-          glob[threshold] = newValue
+          glob[threshold] = formattedValue
         }
       }
     }

packages/vitest/src/node/types/coverage.ts

@@ -279,10 +279,11 @@ interface Thresholds {
 
   /**
    * Update threshold values automatically when current coverage is higher than earlier thresholds
+   * Also can accept a function to format the new threshold values
    *
    * @default false
    */
-  autoUpdate?: boolean
+  autoUpdate?: boolean | ((newThreshold: number) => number)
 
   /** Thresholds for statements */
   statements?: number

test/core/test/cli-test.test.ts

@@ -127,6 +127,13 @@ test('fails when an array is passed down for a single value', async () => {
     .toThrowErrorMatchingInlineSnapshot(`[Error: Expected a single value for option "--coverage.provider <name>", received ["v8", "istanbul"]]`)
 })
 
+test('coverage autoUpdate accepts boolean values from CLI', async () => {
+  expect(getCLIOptions('--coverage.thresholds.autoUpdate true').coverage.thresholds.autoUpdate).toBe(true)
+  expect(getCLIOptions('--coverage.thresholds.autoUpdate false').coverage.thresholds.autoUpdate).toBe(false)
+  expect(getCLIOptions('--coverage.thresholds.autoUpdate yes').coverage.thresholds.autoUpdate).toBe(true)
+  expect(getCLIOptions('--coverage.thresholds.autoUpdate no').coverage.thresholds.autoUpdate).toBe(false)
+})
+
 test('bench only options', async () => {
   expect(() =>
     parseArguments('--compare file.json').matchedCommand?.checkUnknownOptions(),

test/coverage-test/test/threshold-auto-update.unit.test.ts

@@ -2,7 +2,7 @@ import type { CoverageMap } from 'istanbul-lib-coverage'
 import { createCoverageSummary } from 'istanbul-lib-coverage'
 import { parseModule } from 'magicast'
 
-import { expect, test } from 'vitest'
+import { expect, test, vi } from 'vitest'
 import { defineConfig } from 'vitest/config'
 import { BaseCoverageProvider } from 'vitest/coverage'
 
@@ -130,7 +130,33 @@ export default config
   await expect(updateThresholds(config)).rejects.toThrowErrorMatchingInlineSnapshot(`[Error: Failed to update coverage thresholds. Configuration file is too complex.]`)
 })
 
-async function updateThresholds(configurationFile: ReturnType<typeof parseModule>) {
+test('formats values with custom formatter', async () => {
+  const config = parseModule(`export default ${initialConfig}`)
+
+  const autoUpdate = vi.fn().mockImplementation(value => value + 10_000)
+  const updatedConfig = await updateThresholds(config, { thresholds: { autoUpdate } })
+
+  expect(updatedConfig).toMatchInlineSnapshot(`
+    "export default {
+      "test": {
+        "coverage": {
+          "thresholds": {
+            "lines": 10050,
+            "branches": 10060,
+            "functions": 10070,
+            "statements": 10080
+          }
+        }
+      }
+    }"
+  `)
+
+  const calls = autoUpdate.mock.calls.flatMap(call => call[0])
+
+  expect(calls.sort()).toEqual([50, 60, 70, 80])
+})
+
+async function updateThresholds(configurationFile: ReturnType<typeof parseModule>, _coverageOptions: Partial<(InstanceType<typeof BaseCoverageProvider>)['options']> = {}) {
   const summaryData = { total: 0, covered: 0, skipped: 0 }
   const thresholds = [{
     name: 'global',
@@ -151,7 +177,7 @@ async function updateThresholds(configurationFile: ReturnType<typeof parseModule
     provider._initialize({
       config: { coverage: { } },
       logger: { log: () => {} },
-      _coverageOptions: {},
+      _coverageOptions,
     } as any)
 
     provider.updateThresholds({