test: Add coverage for retry package (#33)

internal/retry/retry.go

@@ -6,7 +6,7 @@ import (
 	"time"
 )
 
-const (
+var (
 	defaultMaxRetryTime           = 60 * time.Second
 	defaultMaxRetries             = 100
 	defaultWaitTimeBetweenRetries = 5 * time.Second

internal/retry/retry_test.go

@@ -0,0 +1,272 @@
+package retry
+
+import (
+	"errors"
+	"testing"
+	"time"
+)
+
+func setRetryTimings(t *testing.T) func() {
+	t.Helper()
+	origMaxRetryTime := defaultMaxRetryTime
+	origMaxRetries := defaultMaxRetries
+	origWaitTime := defaultWaitTimeBetweenRetries
+
+	defaultMaxRetryTime = 100 * time.Millisecond
+	defaultMaxRetries = 3
+	defaultWaitTimeBetweenRetries = 10 * time.Millisecond
+
+	return func() {
+		defaultMaxRetryTime = origMaxRetryTime
+		defaultMaxRetries = origMaxRetries
+		defaultWaitTimeBetweenRetries = origWaitTime
+	}
+}
+
+func TestUnlimitedRetry(t *testing.T) {
+	restoreFn := setRetryTimings(t)
+	defer restoreFn()
+
+	tests := []struct {
+		name          string
+		operationFn   func() (string, error)
+		expectedCalls int
+		expectError   bool
+		expectedValue string
+	}{
+		{
+			name: "succeeds on first try",
+			operationFn: func() (string, error) {
+				return "success", nil
+			},
+			expectedCalls: 1,
+			expectedValue: "success",
+			expectError:   false,
+		},
+		{
+			name: "succeeds after multiple retries",
+			operationFn: (func() func() (string, error) {
+				count := 0
+				return func() (string, error) {
+					count++
+					if count < 3 {
+						return "", errors.New("temporary error")
+					}
+					return "success after retries", nil
+				}
+			})(),
+			expectedCalls: 3,
+			expectedValue: "success after retries",
+			expectError:   false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			callCount := 0
+			trackedFn := func() (string, error) {
+				callCount++
+				return tt.operationFn()
+			}
+
+			result, err := UnlimitedRetry("test-operation", trackedFn)
+
+			if tt.expectError && err == nil {
+				t.Error("expected error but got nil")
+			}
+
+			if !tt.expectError && err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+
+			if result != tt.expectedValue {
+				t.Errorf("expected value %v but got %v", tt.expectedValue, result)
+			}
+
+			if callCount != tt.expectedCalls {
+				t.Errorf("expected %d calls but got %d", tt.expectedCalls, callCount)
+			}
+		})
+	}
+}
+
+func TestLimitedRetry(t *testing.T) {
+	restoreFn := setRetryTimings(t)
+	defer restoreFn()
+
+	tests := []struct {
+		name          string
+		operationFn   func() (string, error)
+		expectedCalls int
+		expectError   bool
+		expectedValue string
+	}{
+		{
+			name: "succeeds on first try",
+			operationFn: func() (string, error) {
+				return "success", nil
+			},
+			expectedCalls: 1,
+			expectedValue: "success",
+			expectError:   false,
+		},
+		{
+			name: "succeeds within retry limits",
+			operationFn: (func() func() (string, error) {
+				count := 0
+				return func() (string, error) {
+					count++
+					if count < 3 {
+						return "", errors.New("dummy error")
+					}
+					return "success after retries", nil
+				}
+			})(),
+			expectedCalls: 3,
+			expectedValue: "success after retries",
+			expectError:   false,
+		},
+		{
+			name: "fails after max attempts",
+			operationFn: func() (string, error) {
+				return "", errors.New("persistent error")
+			},
+			expectedCalls: defaultMaxRetries,
+			expectError:   true,
+			expectedValue: "",
+		},
+		{
+			name: "fails after max retry time",
+			operationFn: func() (string, error) {
+				time.Sleep(defaultMaxRetryTime + time.Second)
+				return "", errors.New("timeout error")
+			},
+			expectedCalls: 1,
+			expectError:   true,
+			expectedValue: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			callCount := 0
+			trackedFn := func() (string, error) {
+				callCount++
+				return tt.operationFn()
+			}
+
+			result, err := LimitedRetry("test-operation", trackedFn)
+
+			if tt.expectError && err == nil {
+				t.Error("expected error but got nil")
+			}
+
+			if !tt.expectError && err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+
+			if result != tt.expectedValue {
+				t.Errorf("expected value %v but got %v", tt.expectedValue, result)
+			}
+
+			if callCount != tt.expectedCalls {
+				t.Errorf("expected %d calls but got %d", tt.expectedCalls, callCount)
+			}
+		})
+	}
+}
+
+func TestRetryConfiguration(t *testing.T) {
+	tests := []struct {
+		name string
+		cfg  retryConfig
+		fn   func() (string, error)
+		want error
+	}{
+		{
+			name: "respects custom max retry time",
+			cfg: retryConfig{
+				MaxRetryTime:           100 * time.Millisecond,
+				MaxAttempts:            0,
+				WaitTimeBetweenRetries: time.Millisecond,
+			},
+			fn: func() (string, error) {
+				return "", errors.New("error")
+			},
+			want: errors.New("gave up retrying operation `test` on reaching max retry time 100ms, last error: error"),
+		},
+		{
+			name: "respects custom max attempts",
+			cfg: retryConfig{
+				MaxRetryTime:           0,
+				MaxAttempts:            2,
+				WaitTimeBetweenRetries: time.Millisecond,
+			},
+			fn: func() (string, error) {
+				return "", errors.New("error")
+			},
+			want: errors.New("gave up retrying operation `test` on reaching max retry attempts 2, last error: error"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := retry("test", tt.fn, tt.cfg)
+			if err == nil {
+				t.Fatal("expected error but got nil")
+			}
+
+			if err.Error() != tt.want.Error() {
+				t.Errorf("got error %q, want %q", err, tt.want)
+			}
+		})
+	}
+}
+
+func TestRetryWithDifferentTypes(t *testing.T) {
+	t.Run("works with string", func(t *testing.T) {
+		result, err := UnlimitedRetry("string-operation", func() (string, error) {
+			return "test", nil
+		})
+
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		if result != "test" {
+			t.Errorf("expected string \"test\" but got %s", result)
+		}
+	})
+
+	t.Run("works with int", func(t *testing.T) {
+		result, err := UnlimitedRetry("int-operation", func() (int, error) {
+			return 123, nil
+		})
+
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		if result != 123 {
+			t.Errorf("expected int 123 but got %d", result)
+		}
+	})
+
+	type testStruct struct {
+		value string
+	}
+
+	t.Run("works with struct", func(t *testing.T) {
+		result, err := UnlimitedRetry("struct-operation", func() (testStruct, error) {
+			return testStruct{value: "test"}, nil
+		})
+
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+
+		if result.value != "test" {
+			t.Errorf("expected 'test' in struct.value but got %s", result.value)
+		}
+	})
+}