Feat/support custom fk (#42)

* feat: support custom foreign key * test: add more test case * feat: update readme * refactor: change tag name * feat: update readme --------- Co-authored-by: Eyo Chen <[email protected]>
eyo-chen · Dec 15, 2024 · b960a78 · b960a78
1 parent a07937a
commit b960a78
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Showing 4 changed files with 134 additions and 38 deletions.
diff --git a/association.go b/association.go
@@ -24,6 +24,7 @@ type fkRef struct {
 	tableName    string
 	fieldName    string
 	foreignField string
+	fkName       string
 }
 
 // nodeInfo is used to store the information of a node for later reference.
@@ -131,7 +132,7 @@ func (f *Factory[T]) insertAssocNode(ctx context.Context, nodes []assocNode) ([]
 				}
 
 				// set the foreign key field
-				if err := setForeignKey(v, dep.fieldName, d); err != nil {
+				if err := setForeignKey(v, dep.fieldName, d, dep.fkName); err != nil {
 					return nil, err
 				}
 				if dep.foreignField != "" {
@@ -259,6 +260,7 @@ func (f *Factory[T]) genAssocNodes(nodeInfoMap map[string]nodeInfo) ([]assocNode
 				tableName:    t.tableName,
 				fieldName:    t.fieldName,
 				foreignField: t.foreignField,
+				fkName:       t.fkName,
 			})
 
 			// e.g. User(fk) -> SubCategory
@@ -281,7 +283,7 @@ func (f *Factory[T]) genAssocNodes(nodeInfoMap map[string]nodeInfo) ([]assocNode
 }
 
 // setForeignKey sets the value of the source's ID field to the target's foreign key(name) field
-func setForeignKey(target interface{}, name string, source interface{}) error {
+func setForeignKey(target interface{}, name string, source interface{}, fkName string) error {
 	targetField := reflect.ValueOf(target).Elem().FieldByName(name)
 	if !targetField.IsValid() {
 		return fmt.Errorf("%s: %w", name, errFieldNotFound)
@@ -291,9 +293,9 @@ func setForeignKey(target interface{}, name string, source interface{}) error {
 		return fmt.Errorf("%s: %w", name, errFieldCantSet)
 	}
 
-	sourceIDField := reflect.ValueOf(source).Elem().FieldByName("ID")
+	sourceIDField := reflect.ValueOf(source).Elem().FieldByName(fkName)
 	if !sourceIDField.IsValid() {
-		return fmt.Errorf("%s: %w", "ID", errFieldNotFound)
+		return fmt.Errorf("%s: %w", fkName, errFieldNotFound)
 	}
 
 	sourceIDKind := sourceIDField.Kind()

diff --git a/gofacto_test.go b/gofacto_test.go
@@ -64,11 +64,12 @@ func setIDField(val reflect.Value) error {
 
 // testAssocStruct is a struct with a foreign key to test the association functionality.
 type testAssocStruct struct {
-	ID            int
-	ForeignKey    int  `gofacto:"foreignKey,struct:testStructWithID,field:ForeignValue"`
-	ForeignKey2   *int `gofacto:"foreignKey,struct:testStructWithID2,field:ForeignValue2,table:test_struct_with_id2s"`
-	ForeignValue  testStructWithID
-	ForeignValue2 *testStructWithID2
+	ID               int
+	ForeignKey       int  `gofacto:"foreignKey,struct:testStructWithID,field:ForeignValue"`
+	ForeignKey2      *int `gofacto:"foreignKey,struct:testStructWithID2,field:ForeignValue2,table:test_struct_with_id2s"`
+	CustomForeignKey int  `gofacto:"foreignKey,struct:testStructWithCustomFK,refField:OtherID"`
+	ForeignValue     testStructWithID
+	ForeignValue2    *testStructWithID2
 }
 
 // testStructWithID is a struct with an ID field to test the insert functionality.
@@ -91,6 +92,11 @@ type testStructWithID3 struct {
 	Name string
 }
 
+type testStructWithCustomFK struct {
+	ID      int
+	OtherID int
+}
+
 type testStructWithCycle struct {
 	ID         int
 	ForeignKey int `gofacto:"foreignKey,struct:testStructWithCycle2"`
@@ -2575,18 +2581,19 @@ func setZero_OnBuilderListMany(t *testing.T) {
 
 func TestWithOne(t *testing.T) {
 	for _, fn := range map[string]func(*testing.T){
-		"when on builder, insert successfully":                       withOne_OnBuilder,
-		"when on builder with multi level, insert successfully":      withOne_OnBuilderMultiLevel,
-		"when on builder not pass ptr, return error":                 withOne_OnBuilderNotPassPtr,
-		"when on builder not pass struct, return error":              withOne_OnBuilderNotPassStruct,
-		"when on builder with err, return error":                     withOne_OnBuilderWithErr,
-		"when on builder with cycle, return error":                   withOne_OnBuilderWithCycle,
-		"when on builder list, insert successfully":                  withOne_OnBuilderList,
-		"when on builder list with multi level, insert successfully": withOne_OnBuilderListMultiLevel,
-		"when on builder list not pass ptr, return error":            withOne_OnBuilderListNotPassPtr,
-		"when on builder list not pass struct, return error":         withOne_OnBuilderListNotPassStruct,
-		"when on builder list with err, return error":                withOne_OnBuilderListWithErr,
-		"when on builder list with cycle, return error":              withOne_OnBuilderListWithCycle,
+		"when on builder, insert successfully":                        withOne_OnBuilder,
+		"when on builder with multi level, insert successfully":       withOne_OnBuilderMultiLevel,
+		"when on builder not pass ptr, return error":                  withOne_OnBuilderNotPassPtr,
+		"when on builder not pass struct, return error":               withOne_OnBuilderNotPassStruct,
+		"when on builder with err, return error":                      withOne_OnBuilderWithErr,
+		"when on builder with cycle, return error":                    withOne_OnBuilderWithCycle,
+		"when on builder with wrong custom foreign key, return error": withOne_OnBuilderWithWrongCustomFK,
+		"when on builder list, insert successfully":                   withOne_OnBuilderList,
+		"when on builder list with multi level, insert successfully":  withOne_OnBuilderListMultiLevel,
+		"when on builder list not pass ptr, return error":             withOne_OnBuilderListNotPassPtr,
+		"when on builder list not pass struct, return error":          withOne_OnBuilderListNotPassStruct,
+		"when on builder list with err, return error":                 withOne_OnBuilderListWithErr,
+		"when on builder list with cycle, return error":               withOne_OnBuilderListWithCycle,
 	} {
 		t.Run(testutils.GetFunName(fn), func(t *testing.T) {
 			fn(t)
@@ -2599,7 +2606,12 @@ func withOne_OnBuilder(t *testing.T) {
 
 	assVal := testStructWithID{}
 	assVal2 := testStructWithID2{}
-	val, err := f.Build(mockCTX).WithOne(&assVal).WithOne(&assVal2).Insert()
+	assVal3 := testStructWithCustomFK{}
+	val, err := f.Build(mockCTX).
+		WithOne(&assVal).
+		WithOne(&assVal2).
+		WithOne(&assVal3).
+		Insert()
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
 	}
@@ -2619,6 +2631,10 @@ func withOne_OnBuilder(t *testing.T) {
 	if err := testutils.CompareVal(val.ForeignValue2, &assVal2); err != nil {
 		t.Fatal(err.Error())
 	}
+
+	if val.CustomForeignKey != assVal3.OtherID {
+		t.Fatalf("foreignKey should be %v", assVal3.OtherID)
+	}
 }
 
 func withOne_OnBuilderMultiLevel(t *testing.T) {
@@ -2720,6 +2736,31 @@ func withOne_OnBuilderWithCycle(t *testing.T) {
 	}
 }
 
+func withOne_OnBuilderWithWrongCustomFK(t *testing.T) {
+	type parent struct {
+		ID int `gofacto:"foreignKey,struct:child,refField:WrongFk"`
+	}
+
+	type child struct {
+		ID      int
+		OtherID int
+	}
+
+	f := New(parent{}).WithDB(&mockDB{})
+
+	want := parent{}
+	wantErr := errFieldNotFound
+
+	val, err := f.Build(mockCTX).WithOne(&child{}).Insert()
+	if !errors.Is(err, wantErr) {
+		t.Fatalf("error should be %v", wantErr)
+	}
+
+	if err := testutils.CompareVal(val, want); err != nil {
+		t.Fatal(err.Error())
+	}
+}
+
 func withOne_OnBuilderList(t *testing.T) {
 	f := New(testAssocStruct{}).WithDB(&mockDB{})
 
@@ -2889,7 +2930,13 @@ func withMany_CorrectCase(t *testing.T) {
 	assVal2 := testStructWithID{}
 	assVal3 := testStructWithID2{}
 	assVal4 := testStructWithID2{}
-	vals, err := f.BuildList(mockCTX, 2).WithMany([]interface{}{&assVal1, &assVal2}).WithMany([]interface{}{&assVal3, &assVal4}).Insert()
+	assVal5 := testStructWithCustomFK{}
+	assVal6 := testStructWithCustomFK{}
+	vals, err := f.BuildList(mockCTX, 2).
+		WithMany([]interface{}{&assVal1, &assVal2}).
+		WithMany([]interface{}{&assVal3, &assVal4}).
+		WithMany([]interface{}{&assVal5, &assVal6}).
+		Insert()
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
 	}
@@ -2925,6 +2972,14 @@ func withMany_CorrectCase(t *testing.T) {
 	if err := testutils.CompareVal(vals[1].ForeignValue2, &assVal4); err != nil {
 		t.Fatal(err.Error())
 	}
+
+	if vals[0].CustomForeignKey != assVal5.OtherID {
+		t.Fatalf("CustomForeignKey should be %v", assVal5.OtherID)
+	}
+
+	if vals[1].CustomForeignKey != assVal6.OtherID {
+		t.Fatalf("CustomForeignKey should be %v", assVal6.OtherID)
+	}
 }
 
 func withMany_MultiLevel(t *testing.T) {

diff --git a/readme.md b/readme.md
@@ -196,11 +196,7 @@ type Order struct {
   Amount      float64
 }
 ```
-The format of the tag is following:<br>
-`gofacto:"foreignKey,struct:{{structName}},table:{{tableName}},field:{{fieldName}}"`<br>
-- `struct` is the name of the associated struct. It is required.<br>
-- `table` is the name of the table. It is optional, the snake case of the struct name(s) will be used if not provided.<br>
-- `field` is the name of the foreign value fields within the struct. It is optional.
+You can find more details about the tag format in [foreignKey tag](#foreignkey-tag).
 
 ```go
 // build an order with one customer
@@ -287,8 +283,6 @@ Find out more [examples](https://github.com/eyo-chen/gofacto/blob/main/examples/
     }
 </details>
 
-
-
 ### Reset
 Use `Reset` method to reset the factory.
 ```go
@@ -299,7 +293,7 @@ factory.Reset()
 &nbsp;
 
 ### Set Configurations
-#### WithBlueprint
+### WithBlueprint
 Use `WithBlueprint` method to set the blueprint function which is a clients defined function to generate the struct values.
 ```go
 func blueprint(i int) *Order {
@@ -319,7 +313,7 @@ The signature of the blueprint function is following:<br>
 
 Find out more [examples](https://github.com/eyo-chen/gofacto/blob/main/examples/blueprint_test.go).
 
-#### WithStorageName
+### WithStorageName
 Use `WithStorageName` method to set the storage name.
 ```go
 factory := gofacto.New(Order{}).
@@ -332,7 +326,7 @@ When using NoSQL databases, the storage name is the collection name. <br>
 
 It is optional, the snake case of the struct name(s) will be used if not provided.<br>
 
-#### WithDB
+### WithDB
 Use `WithDB` method to set the database connection.
 ```go
 factory := gofacto.New(Order{}).
@@ -343,7 +337,7 @@ When using raw PostgreSQL, use `postgresf` package. <br>
 When using MongoDB, use `mongof` package. <br>
 When using GORM, use `gormf` package. <br>
 
-#### WithIsSetZeroValue
+### WithIsSetZeroValue
 Use `WithIsSetZeroValue` method to set if the zero values are set.
 ```go
 factory := gofacto.New(Order{}).
@@ -353,7 +347,37 @@ The zero values will not be set when building the struct if the flag is set to f
 
 It is optional, it's true by default.
 
-#### omit tag
+### foreignKey tag
+In order to build the struct with the associated struct, we need to set the correct tag in the struct to tell gofacto how to build the associated struct.
+
+Suppose we have the following structs:<br>
+`Project` struct has a foreign key `EmployeeID` to reference to `Employee` struct.
+```go
+type Project struct {
+  ID          int
+  EmployeeID  int `gofacto:"foreignKey,struct:Employee,table:employees,field:Employee,refField:OtherID"`
+  Employee    Employee
+}
+
+type Employee struct {
+  ID      int
+  OtherID int
+  Name    string
+}
+```
+
+The format of the tag is following:<br>
+`gofacto:"foreignKey,struct:{{structName}},table:{{tableName}},field:{{fieldName}},refField:{{referenceFieldName}}"`<br>
+- `foreignKey` is the tag name. It is required.
+- `struct` specifies the name of the associated struct. It is required. In this case, `struct:Employee` indicates that `EmployeeID` is a foreign key to reference to `Employee` struct.
+- `table` specifies the table name of the associated struct. It is optional, the snake case and lower case of the struct name(s) will be used if not provided. In this case, `table:employees` indicates that the table name of `Employee` struct is `employees`. However, we can omit it and gofacto will handle it in this example.
+- `field` specifies which struct field contains the associated data. It is optional, and it's typically used with gorm. In this example, `field:Employee` indicates that the `Employee` field in the `Project` struct will hold the related `Employee` data after the relationship is loaded.
+- `refField` specifies which field to join on in the referenced struct. By default, it joins on the `ID` field, but you can specify a different field. For example, `refField:OtherID` tells gofacto to match `Project.EmployeeID` with `Employee.OtherID` instead of `Employee.ID`.
+
+Find out more [examples](https://github.com/eyo-chen/gofacto/blob/main/examples/association_test.go).
+
+
+### omit tag
 Use `omit` tag in the struct to ignore the field when building the struct.
 ```go
 type Order struct {

diff --git a/tag.go b/tag.go
@@ -7,11 +7,20 @@ import (
 	"github.com/eyo-chen/gofacto/internal/utils"
 )
 
+const (
+	defaultFkName  = "ID"
+	tagKeyStruct   = "struct"
+	tagKeyTable    = "table"
+	tagKeyField    = "field"
+	tagKeyRefField = "refField"
+)
+
 // tag represents the metadata parsed from the custom tag
 type tag struct {
 	fieldName    string
 	structName   string
 	tableName    string
+	fkName       string
 	foreignField string
 	omit         bool
 }
@@ -85,12 +94,14 @@ func parseTag(field reflect.StructField) (tag, bool, error) {
 		for _, subPart := range subParts[1:] {
 			kv := strings.SplitN(subPart, ":", 2)
 			switch kv[0] {
-			case "struct":
+			case tagKeyStruct:
 				t.structName = kv[1]
-			case "table":
+			case tagKeyTable:
 				t.tableName = kv[1]
-			case "field":
+			case tagKeyField:
 				t.foreignField = kv[1]
+			case tagKeyRefField:
+				t.fkName = kv[1]
 			default:
 				return tag{}, false, errTagFormat
 			}
@@ -101,5 +112,9 @@ func parseTag(field reflect.StructField) (tag, bool, error) {
 		t.tableName = utils.CamelToSnake(t.structName) + "s"
 	}
 
+	if t.fkName == "" {
+		t.fkName = defaultFkName
+	}
+
 	return t, true, nil
 }