sql/internal/sqlx: support diffing triggers (#2380)

.golangci.yml

@@ -16,6 +16,9 @@ issues:
     - path: sql/migrate/lex.go
       linters:
         - revive
+    - path: sql/internal/sqlx/diff.go
+      linters:
+        - revive
 
 linters-settings:
   goheader:

cmd/atlas/internal/cmdlog/cmdlog.go

@@ -709,9 +709,15 @@ func sqlInspect(report *SchemaInspect, indent ...string) (string, error) {
 		}
 		for _, t := range s.Tables {
 			changes = append(changes, &schema.AddTable{T: t})
+			for _, r := range t.Triggers {
+				changes = append(changes, &schema.AddTrigger{T: r})
+			}
 		}
 		for _, v := range s.Views {
 			changes = append(changes, &schema.AddView{V: v})
+			for _, r := range v.Triggers {
+				changes = append(changes, &schema.AddTrigger{T: r})
+			}
 		}
 		for _, f := range s.Funcs {
 			changes = append(changes, &schema.AddFunc{F: f})

sql/internal/sqlx/diff.go

@@ -100,6 +100,13 @@ type (
 		// from one schema state to the other.
 		ProcFuncsDiff(from, to *schema.Schema, opts *schema.DiffOptions) ([]schema.Change, error)
 	}
+
+	// TriggerDiffer is an optional interface allows DiffDriver to diff triggers.
+	TriggerDiffer interface {
+		// TriggerDiff returns a changeset for migrating triggers from
+		// one state to the other. For example, changing action time.
+		TriggerDiff(from, to *schema.Trigger) ([]schema.Change, error)
+	}
 )
 
 // RealmDiff implements the schema.Differ for Realm objects and returns a list of changes
@@ -144,9 +151,15 @@ func (d *Diff) RealmDiff(from, to *schema.Realm, options ...schema.DiffOption) (
 		}
 		for _, t := range s1.Tables {
 			changes = opts.AddOrSkip(changes, &schema.AddTable{T: t})
+			for _, r := range t.Triggers {
+				changes = opts.AddOrSkip(changes, &schema.AddTrigger{T: r})
+			}
 		}
 		for _, v := range s1.Views {
 			changes = opts.AddOrSkip(changes, &schema.AddView{V: v})
+			for _, r := range v.Triggers {
+				changes = opts.AddOrSkip(changes, &schema.AddTrigger{T: r})
+			}
 		}
 	}
 	return d.mayAnnotate(changes, opts)
@@ -186,20 +199,24 @@ func (d *Diff) schemaDiff(from, to *schema.Schema, opts *schema.DiffOptions) ([]
 	for _, t1 := range from.Tables {
 		switch t2, err := d.findTable(to, t1.Name); {
 		case schema.IsNotExistError(err):
+			// Triggers should be dropped either by the driver or the database.
 			changes = opts.AddOrSkip(changes, &schema.DropTable{T: t1})
 		case err != nil:
 			return nil, err
 		default:
-			change, err := d.tableDiff(t1, t2, opts)
-			if err != nil {
+			if change, err := d.tableDiff(t1, t2, opts); err != nil {
 				return nil, err
-			}
-			if len(change) > 0 {
+			} else if len(change) > 0 {
 				changes = opts.AddOrSkip(changes, &schema.ModifyTable{
 					T:       t2,
 					Changes: change,
 				})
 			}
+			if change, err := d.triggerDiff(t1, t2, t1.Triggers, t2.Triggers, opts); err != nil {
+				return nil, err
+			} else {
+				changes = append(changes, change...)
+			}
 		}
 	}
 	// Add tables.
@@ -220,10 +237,14 @@ func (d *Diff) schemaDiff(from, to *schema.Schema, opts *schema.DiffOptions) ([]
 			changes = opts.AddOrSkip(changes, &schema.DropView{V: v1})
 			continue
 		}
-		change := d.indexDiffV(v1, v2, opts)
-		if d.viewDefChanged(v1, v2) || d.ViewAttrChanged(v1, v2) || len(change) > 0 {
+		if change := d.indexDiffV(v1, v2, opts); d.viewDefChanged(v1, v2) || d.ViewAttrChanged(v1, v2) || len(change) > 0 {
 			changes = opts.AddOrSkip(changes, &schema.ModifyView{From: v1, To: v2, Changes: change})
 		}
+		if change, err := d.triggerDiff(v1, v2, v1.Triggers, v2.Triggers, opts); err != nil {
+			return nil, err
+		} else {
+			changes = append(changes, change...)
+		}
 	}
 	// Add views.
 	for _, v1 := range to.Views {
@@ -253,6 +274,11 @@ func (d *Diff) TableDiff(from, to *schema.Table, options ...schema.DiffOption) (
 	if err != nil {
 		return nil, err
 	}
+	if change, err := d.triggerDiff(from, to, from.Triggers, to.Triggers, opts); err != nil {
+		return nil, err
+	} else {
+		changes = append(changes, change...)
+	}
 	return d.mayAnnotate(changes, opts)
 }
 

sql/internal/sqlx/sqlx_oss.go

@@ -14,3 +14,9 @@ import (
 func sortViewChanges(changes []schema.Change) ([]schema.Change, error) {
 	return changes, nil // unimplemented.
 }
+
+func (*Diff) triggerDiff(_, _ interface {
+	Trigger(string) (*schema.Trigger, bool)
+}, _, _ []*schema.Trigger, _ *schema.DiffOptions) ([]schema.Change, error) {
+	return nil, nil // unimplemented.
+}

sql/schema/schema.go

@@ -307,6 +307,16 @@ func (t *Table) ForeignKey(symbol string) (*ForeignKey, bool) {
 	return nil, false
 }
 
+// Trigger returns the first trigger that matches the given name.
+func (t *Table) Trigger(name string) (*Trigger, bool) {
+	for _, r := range t.Triggers {
+		if r.Name == name {
+			return r, true
+		}
+	}
+	return nil, false
+}
+
 // Materialized reports if the view is materialized.
 func (v *View) Materialized() bool {
 	for _, a := range v.Attrs {
@@ -347,6 +357,16 @@ func (v *View) Index(name string) (*Index, bool) {
 	return nil, false
 }
 
+// Trigger returns the first trigger that matches the given name.
+func (v *View) Trigger(name string) (*Trigger, bool) {
+	for _, r := range v.Triggers {
+		if r.Name == name {
+			return r, true
+		}
+	}
+	return nil, false
+}
+
 // AsTable returns a table that represents the view.
 func (v *View) AsTable() *Table {
 	return NewTable(v.Name).