OCPBUGS-66051: Adds the parser package

v2/internal/pkg/parser/parse.go

@@ -0,0 +1,63 @@
+//nolint:ireturn // generic T should be fine to return here
+package parser
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"sigs.k8s.io/yaml"
+)
+
+// ParseJsonFile reads json `file` and parses it as type T
+func ParseJsonFile[T any](file string) (T, error) {
+	var t T
+	data, err := os.ReadFile(file)
+	if err != nil {
+		return t, fmt.Errorf("read file: %w", err)
+	}
+	if err := json.Unmarshal(data, &t); err != nil {
+		return t, fmt.Errorf("parse file: %w", err)
+	}
+	return t, nil
+}
+
+// ParseJsonReader parses json from a stream into a type T
+func ParseJsonReader[T any](r io.Reader) (T, error) {
+	var t T
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return t, fmt.Errorf("read stream: %w", err)
+	}
+	if err := json.Unmarshal(data, &t); err != nil {
+		return t, fmt.Errorf("parse stream: %w", err)
+	}
+	return t, nil
+}
+
+// ParseYamlFile reads yaml `file` and parses it as type T
+func ParseYamlFile[T any](file string) (T, error) {
+	var t T
+	data, err := os.ReadFile(file)
+	if err != nil {
+		return t, fmt.Errorf("read file: %w", err)
+	}
+	if err := yaml.Unmarshal(data, &t); err != nil {
+		return t, fmt.Errorf("parse file: %w", err)
+	}
+	return t, nil
+}
+
+// ParseYamlReader parses yaml from a stream into a type T
+func ParseYamlReader[T any](r io.Reader) (T, error) {
+	var t T
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return t, fmt.Errorf("read stream: %w", err)
+	}
+	if err := yaml.Unmarshal(data, &t); err != nil {
+		return t, fmt.Errorf("parse stream: %w", err)
+	}
+	return t, nil
+}

v2/internal/pkg/parser/parse_test.go

@@ -0,0 +1,59 @@
+package parser
+
+import (
+	"os"
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseJsonFromFile(t *testing.T) {
+	type custom struct{ field string } //nolint:unused // just a dummy type
+	// We don't really need to test this functionality.
+	// These tests exist just to sanity check the error messages.
+	t.Run("Testing ParseJsonFile should fail", func(t *testing.T) {
+		t.Run("with invalid file", func(t *testing.T) {
+			res, err := ParseJsonFile[custom]("invalid-file")
+			assert.Empty(t, res)
+			assert.Error(t, err)
+			assert.Regexp(t, "read file: open .*: no such file or directory", err)
+		})
+
+		t.Run("with malformed json", func(t *testing.T) {
+			filePath := path.Join(t.TempDir(), "index.json")
+			err := os.WriteFile(filePath, []byte("invalid"), 0o644) //nolint:gosec // temp file
+			assert.NoError(t, err, "should create invalid index.json")
+
+			res, err := ParseJsonFile[custom](filePath)
+			assert.Empty(t, res)
+			assert.Error(t, err)
+			assert.Regexp(t, "parse file: .*", err)
+		})
+	})
+}
+
+func TestParseYamlFromFile(t *testing.T) {
+	type custom struct{ field string } //nolint:unused // just a dummy type
+	// We don't really need to test this functionality.
+	// These tests exist just to sanity check the error messages.
+	t.Run("Testing ParseYamlFile should fail", func(t *testing.T) {
+		t.Run("with invalid file", func(t *testing.T) {
+			res, err := ParseYamlFile[custom]("invalid-file")
+			assert.Empty(t, res)
+			assert.Error(t, err)
+			assert.Regexp(t, "read file: open .*: no such file or directory", err)
+		})
+
+		t.Run("with malformed yaml", func(t *testing.T) {
+			filePath := path.Join(t.TempDir(), "index.yaml")
+			err := os.WriteFile(filePath, []byte("invalid\nyaml"), 0o644) //nolint:gosec // temp file
+			assert.NoError(t, err, "should create invalid index.yaml")
+
+			res, err := ParseYamlFile[custom](filePath)
+			assert.Empty(t, res)
+			assert.Error(t, err)
+			assert.Regexp(t, "parse file: .*", err)
+		})
+	})
+}