Added unit tests for the tools/codegen package (#15016)

Signed-off-by: VaibhavMalik4187 <[email protected]>

go/tools/codegen/common_test.go

@@ -0,0 +1,105 @@
+/*
+Copyright 2024 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package codegen
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/tools/go/packages"
+)
+
+func TestCheckErrors(t *testing.T) {
+	tests := []struct {
+		name        string
+		loaded      []*packages.Package
+		expectedErr string
+	}{
+		{
+			name:        "Empty packages",
+			loaded:      []*packages.Package{},
+			expectedErr: "",
+		},
+		{
+			name: "Non-empty packages",
+			loaded: []*packages.Package{
+				{
+					Errors: []packages.Error{
+						{
+							Pos:  "",
+							Msg:  "New error",
+							Kind: 7,
+						},
+						{
+							Pos:  "1:7",
+							Msg:  "New error",
+							Kind: 7,
+						},
+					},
+				},
+			},
+			expectedErr: "found 2 error(s) when loading Go packages:",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := CheckErrors(tt.loaded, GeneratedInSqlparser)
+			if tt.expectedErr == "" {
+				require.NoError(t, err)
+			} else {
+				require.ErrorContains(t, err, tt.expectedErr)
+			}
+		})
+	}
+}
+
+func TestGeneratedInSqlParser(t *testing.T) {
+	tests := []struct {
+		name           string
+		fileName       string
+		expectedOutput bool
+	}{
+		{
+			name:           "Empty file name",
+			fileName:       "",
+			expectedOutput: false,
+		},
+		{
+			name:           "Random file name",
+			fileName:       "random",
+			expectedOutput: false,
+		},
+		{
+			name:           "ast_format_fast.go",
+			fileName:       "ast_format_fast.go",
+			expectedOutput: true,
+		},
+		{
+			name:           "ast_equals.go",
+			fileName:       "ast_equals.go",
+			expectedOutput: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expectedOutput, GeneratedInSqlparser(tt.fileName))
+		})
+	}
+}

go/tools/codegen/goimports_test.go

@@ -0,0 +1,90 @@
+/*
+Copyright 2024 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package codegen
+
+import (
+	"testing"
+
+	"github.com/dave/jennifer/jen"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFormatGenFile(t *testing.T) {
+	tests := []struct {
+		name        string
+		file        *jen.File
+		expectedErr string
+	}{
+		{
+			name:        "some-file",
+			file:        jen.NewFile("some-file"),
+			expectedErr: "Error 1:13: expected ';', found '-' while formatting source",
+		},
+		{
+			name: "random",
+			file: jen.NewFile("random"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := FormatJenFile(tt.file)
+			if tt.expectedErr == "" {
+				require.NoError(t, err)
+			} else {
+				require.ErrorContains(t, err, tt.expectedErr)
+			}
+		})
+	}
+}
+
+func TestGoImports(t *testing.T) {
+	err := GoImports("")
+	require.ErrorContains(t, err, "exit status 2")
+}
+
+func TestSaveJenFile(t *testing.T) {
+	tests := []struct {
+		name        string
+		filePath    string
+		file        *jen.File
+		expectedErr string
+	}{
+		{
+			name:        "Empty file path",
+			filePath:    "",
+			file:        jen.NewFile("random"),
+			expectedErr: "open : no such file or directory",
+		},
+		{
+			name:     "Non empty file path",
+			filePath: "random",
+			file:     jen.NewFile("random"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := SaveJenFile(tt.filePath, tt.file)
+			if tt.expectedErr == "" {
+				require.NoError(t, err)
+			} else {
+				require.ErrorContains(t, err, tt.expectedErr)
+			}
+		})
+	}
+}