feat: many2many relations check

tests/relations_check_test.go

@@ -0,0 +1,12 @@
+package tests
+
+import (
+	"golang.org/x/tools/go/analysis/analysistest"
+	"gormlint/relationsCheck"
+	"testing"
+)
+
+func TestRelationsCheck(t *testing.T) {
+	t.Parallel()
+	analysistest.Run(t, analysistest.TestData(), relationsCheck.RelationsAnalyzer, "relations_check")
+}

tests/testdata/src/references_check/negative.go

@@ -1,5 +1,7 @@
 package references_check
 
+// TODO: add test with annotations on back-references
+
 type WorkArea struct {
 	Id         uint     `gorm:"primaryKey"`
 	Workshop   Workshop `gorm:"foreignKey:WorkshopId;references:Id;"`

tests/testdata/src/references_check/positive.go

@@ -1,5 +1,7 @@
 package references_check
 
+// TODO: add test with annotations on back-references
+
 type User struct {
 	Name      string
 	CompanyID string

tests/testdata/src/relations_check/negative.go

@@ -0,0 +1,16 @@
+package relations_check
+
+type Library struct {
+	Id    uint    `gorm:"primaryKey"`
+	Books []*Book `gorm:"many2many:library_book;"`
+}
+
+type Book struct {
+	Id        uint       `gorm:"primaryKey"`
+	Libraries []*Library `gorm:"many2many:library_book;"`
+}
+
+type Employee struct {
+	Id           uint        `gorm:"primaryKey"`
+	Subordinates []*Employee `gorm:"many2many:employee_subordinates;"` // self-reference
+}

tests/testdata/src/relations_check/positive.go

@@ -0,0 +1,21 @@
+package relations_check
+
+type Student struct {
+	Id      uint     `gorm:"primaryKey"`
+	Courses []Course `gorm:"many2many:student_courses;"`
+}
+
+type Course struct {
+	Id       uint     `gorm:"primaryKey"`
+	Students []Course `gorm:"many2many:student_courses;"` // want "Invalid type `Course` in M2M relation \\(use \\[\\]\\*Student or self-reference\\)"
+}
+
+type Author struct {
+	Id       uint      `gorm:"primaryKey"`
+	Articles []Article `gorm:"many2many:author_articles;"`
+}
+
+type Article struct {
+	Id      uint   `gorm:"primaryKey"`
+	Authors Author `gorm:"many2many:author_articles;"` // want "M2M relation `author_articles` with bad type `Author` \\(should be a slice\\)"
+}