Add coverage percentage display to test output

README.md

@@ -48,6 +48,12 @@ Powered by [Job Summaries](https://github.blog/2022-05-09-supercharging-github-a
     #  stderr: standard error output of `go test` subprocess
     # Optional. No default
     omit:
+
+    # Generate coverage profile and display coverage percentage.
+    # Specify the coverage file path (e.g., "coverage.out").
+    # When set, coverage percentages will be displayed in the summary table.
+    # Optional. No default
+    coverprofile:
 ```
 
 ## Screenshots
@@ -97,6 +103,15 @@ jobs:
     fromJSONFile: /path/to/test2json.json
 ```
 
+### With coverage
+
+```yaml
+- name: Test
+  uses: robherley/go-test-action@v0
+  with:
+    coverprofile: coverage.out
+```
+
 ### Omitting elements
 
 See [Inputs](#inputs) above for valid options

__tests__/events.test.ts

@@ -89,4 +89,18 @@ describe('events', () => {
     const otherTestEvents = parseTestEvents(otherStdout)
     expect(otherTestEvents[0]).toHaveProperty('isCached', false)
   })
+
+  it('correctly parses coverage percentage', () => {
+    const coverageStdout =
+      '{"Time":"2025-12-13T04:41:53.511365498Z","Action":"output","Package":"example.com/test","Output":"coverage: 50.0% of statements\\n"}'
+
+    const coverageEvents = parseTestEvents(coverageStdout)
+    expect(coverageEvents[0]).toHaveProperty('coverage', 50.0)
+
+    const noCoverageStdout =
+      '{"Time":"2022-07-10T22:42:11.931552-04:00","Action":"output","Package":"github.com/robherley/go-test-example/success","Output":"ok  \\tgithub.com/robherley/go-test-example/success\\n"}'
+
+    const noCoverageEvents = parseTestEvents(noCoverageStdout)
+    expect(noCoverageEvents[0]).toHaveProperty('coverage', undefined)
+  })
 })

__tests__/fixtures/gotestoutput_coverage.txt

@@ -0,0 +1,9 @@
+{"Time":"2025-12-13T04:41:53.509319636Z","Action":"start","Package":"example.com/test"}
+{"Time":"2025-12-13T04:41:53.510906756Z","Action":"run","Package":"example.com/test","Test":"TestAdd"}
+{"Time":"2025-12-13T04:41:53.510923518Z","Action":"output","Package":"example.com/test","Test":"TestAdd","Output":"=== RUN   TestAdd\n"}
+{"Time":"2025-12-13T04:41:53.510972229Z","Action":"output","Package":"example.com/test","Test":"TestAdd","Output":"--- PASS: TestAdd (0.00s)\n"}
+{"Time":"2025-12-13T04:41:53.510985845Z","Action":"pass","Package":"example.com/test","Test":"TestAdd","Elapsed":0}
+{"Time":"2025-12-13T04:41:53.510994671Z","Action":"output","Package":"example.com/test","Output":"PASS\n"}
+{"Time":"2025-12-13T04:41:53.511365498Z","Action":"output","Package":"example.com/test","Output":"coverage: 50.0% of statements\n"}
+{"Time":"2025-12-13T04:41:53.511714866Z","Action":"output","Package":"example.com/test","Output":"ok  \texample.com/test\t0.002s\tcoverage: 50.0% of statements\n"}
+{"Time":"2025-12-13T04:41:53.511732649Z","Action":"pass","Package":"example.com/test","Elapsed":0.002}

__tests__/inputs.test.ts

@@ -26,6 +26,7 @@ describe('renderer', () => {
       testArguments: ['./...'],
       fromJSONFile: null,
       omit: new Set(),
+      coverprofile: null,
     })
   })
 
@@ -50,6 +51,13 @@ describe('renderer', () => {
     expect(inputs.fromJSONFile).toEqual('foo.json')
   })
 
+  it('parses coverprofile', () => {
+    mockInput('coverprofile', 'coverage.out')
+    const inputs = getInputs()
+
+    expect(inputs.coverprofile).toEqual('coverage.out')
+  })
+
   it('parses omit', () => {
     mockInput(
       'omit',

action.yml

@@ -33,6 +33,9 @@ inputs:
     description: 'Omit any packages from summary output that are successful'
     required: false
     default: 'false'
+  coverprofile:
+    description: 'Generate coverage profile and display coverage percentage. Specify the coverage file path (e.g., "coverage.out")'
+    required: false
 runs:
   using: 'node20'
   main: 'dist/index.js'

src/events.ts

@@ -36,6 +36,7 @@ export interface TestEvent {
   isPackageLevel: boolean
   isConclusive: boolean
   isCached: boolean
+  coverage?: number // percentage (e.g., 50.0 for 50.0%)
 }
 
 /**
@@ -50,6 +51,16 @@ export function parseTestEvents(stdout: string): TestEvent[] {
   for (let line of lines) {
     try {
       const json = JSON.parse(line)
+
+      // Parse coverage percentage from output
+      let coverage: number | undefined
+      if (json.Output) {
+        const coverageMatch = json.Output.match(/coverage:\s*(\d+(?:\.\d+)?)%\s+of\s+statements/)
+        if (coverageMatch) {
+          coverage = parseFloat(coverageMatch[1])
+        }
+      }
+
       events.push({
         time: json.Time && new Date(json.Time),
         action: json.Action as TestEventAction,
@@ -61,6 +72,7 @@ export function parseTestEvents(stdout: string): TestEvent[] {
         isSubtest: json.Test?.includes('/') || false, // afaik there isn't a better indicator in test2json
         isPackageLevel: typeof json.Test === 'undefined',
         isConclusive: conclusiveTestEvents.includes(json.Action),
+        coverage,
       })
     } catch {
       core.debug(`unable to parse line: ${line}`)

src/inputs.ts

@@ -5,6 +5,7 @@ export interface Inputs {
   testArguments: string[]
   fromJSONFile: string | null
   omit: Set<OmitOption>
+  coverprofile: string | null
 }
 
 export enum OmitOption {
@@ -27,6 +28,7 @@ export const defaultInputs = (): Inputs => ({
   testArguments: ['./...'],
   fromJSONFile: null,
   omit: new Set(),
+  coverprofile: null,
 })
 
 /**
@@ -65,6 +67,11 @@ export function getInputs(): Inputs {
       .forEach(option => inputs.omit.add(option as OmitOption))
   }
 
+  const coverprofile = core.getInput('coverprofile')
+  if (coverprofile) {
+    inputs.coverprofile = coverprofile
+  }
+
   return inputs
 }
 

src/renderer.ts

@@ -18,6 +18,7 @@ class Renderer {
   stderr: string
   omit: Set<OmitOption>
   packageResults: PackageResult[]
+  private hasCoverage: boolean = false
   headers: SummaryTableRow = [
     { data: '📦 Package', header: true },
     { data: '🟢 Passed', header: true },
@@ -42,6 +43,7 @@ class Renderer {
     this.stderr = stderr
     this.omit = omit
     this.packageResults = this.calculatePackageResults()
+    this.setupHeaders()
   }
 
   /**
@@ -73,6 +75,20 @@ class Renderer {
       .write()
   }
 
+  /**
+   * Setup table headers based on whether coverage data is available
+   */
+  private setupHeaders() {
+    // Check if any package has coverage data
+    this.hasCoverage = this.packageResults.some(
+      result => result.coverage !== undefined
+    )
+
+    if (this.hasCoverage) {
+      this.headers.push({ data: '📊 Coverage', header: true })
+    }
+  }
+
   /**
    * Filters package results based on omit options
    * @returns filtered package results to render
@@ -211,18 +227,27 @@ class Renderer {
       packageResult.packageEvent.package === this.moduleName ? ' (main)' : ''
     }</code>`
 
-    const packageRows: SummaryTableRow[] = [
-      [
-        pkgName,
-        packageResult.conclusions.pass.toString(),
-        packageResult.conclusions.fail.toString(),
-        packageResult.conclusions.skip.toString(),
-        `${(packageResult.packageEvent.elapsed || 0) * 1000}ms`,
-      ],
+    const baseRow = [
+      pkgName,
+      packageResult.conclusions.pass.toString(),
+      packageResult.conclusions.fail.toString(),
+      packageResult.conclusions.skip.toString(),
+      `${(packageResult.packageEvent.elapsed || 0) * 1000}ms`,
     ]
 
+    if (this.hasCoverage) {
+      baseRow.push(
+        packageResult.coverage !== undefined
+          ? `${packageResult.coverage.toFixed(1)}%`
+          : 'N/A'
+      )
+    }
+
+    const packageRows: SummaryTableRow[] = [baseRow]
+
     if (details) {
-      packageRows.push([{ data: details, colspan: '5' }])
+      const colspan = this.hasCoverage ? '6' : '5'
+      packageRows.push([{ data: details, colspan }])
     }
 
     return packageRows

src/results.ts

@@ -17,6 +17,7 @@ class PackageResult {
     fail: 0,
     skip: 0,
   }
+  coverage?: number
 
   constructor(packageEvent: TestEvent, events: TestEvent[]) {
     this.packageEvent = packageEvent
@@ -25,6 +26,11 @@ class PackageResult {
     )
 
     this.eventsToResults()
+
+    // Extract coverage from package-level event if present
+    if (this.packageEvent.coverage !== undefined) {
+      this.coverage = this.packageEvent.coverage
+    }
   }
 
   public testCount(): number {

src/runner.ts

@@ -125,9 +125,17 @@ class Runner {
       },
     })
 
+    const testArgs = ['-json']
+
+    if (this.inputs.coverprofile) {
+      testArgs.push('-coverprofile', this.inputs.coverprofile)
+    }
+
+    testArgs.push(...this.inputs.testArguments)
+
     const retCode = await exec(
       'go',
-      ['test', '-json', ...this.inputs.testArguments],
+      ['test', ...testArgs],
       {
         cwd: this.inputs.moduleDirectory,
         ignoreReturnCode: true,