Merge pull request #70 from avast/unwrap_error_support

feat: unwrap error support (issue #65)

.github/workflows/workflow.yaml

@@ -38,10 +38,24 @@ jobs:
         run: make setup
       - name: Test
         run: make ci
+      - name: Archive code coverage results
+        uses: actions/upload-artifact@v3
+        with:
+          name: code-coverage-report-${{ matrix.os }}
+          path: coverage.txt
+
+  coverage:
+    needs: tests
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download a linux coverage report
+        uses: actions/download-artifact@v3
+        with:
+          name: code-coverage-report-ubuntu-latest
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v3
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
-          env_vars: OS, GOVERSION
           fail_ci_if_error: true
           flags: unittest

README.md

@@ -175,6 +175,25 @@ error interface
 func (e Error) Is(target error) bool
 ```
 
+#### func (Error) Unwrap
+
+```go
+func (e Error) Unwrap() error
+```
+Unwrap the last error for compatible with the `errors.Unwrap()` when you need
+unwrap all erros, you should use `WrappedErrors()` instead
+
+    err := Do(
+    	func() error {
+    		return errors.New("original error")
+    	},
+    	Attempts(1),
+    )
+
+    fmt.Println(errors.Unwrap(err)) # "original error" is printed
+
+added in version 4.1.0
+
 #### func (Error) WrappedErrors
 
 ```go

VERSION

@@ -1 +1 @@
-4.0.3
+4.1.0

retry.go

@@ -209,6 +209,25 @@ func (e Error) As(target interface{}) bool {
 	return false
 }
 
+/*
+Unwrap the last error for compatible with the `errors.Unwrap()`
+when you need unwrap all erros, you should use `WrappedErrors()` instead
+
+	err := Do(
+		func() error {
+			return errors.New("original error")
+		},
+		Attempts(1),
+	)
+
+	fmt.Println(errors.Unwrap(err)) # "original error" is printed
+
+added in version 4.1.0
+*/
+func (e Error) Unwrap() error {
+	return e[len(e)-1]
+}
+
 func lenWithoutNil(e Error) (count int) {
 	for _, v := range e {
 		if v != nil {

retry_test.go

@@ -472,3 +472,16 @@ func TestErrorAs(t *testing.T) {
 	assert.False(t, errors.As(e, &tb))
 	assert.Equal(t, "foo", tf.str)
 }
+
+func TestUnwrap(t *testing.T) {
+	testError := errors.New("test error")
+	err := Do(
+		func() error {
+			return testError
+		},
+		Attempts(1),
+	)
+
+	assert.Error(t, err)
+	assert.Equal(t, testError, errors.Unwrap(err))
+}