fix: order function recreation after dependent view recreation (#480)

internal/diff/diff.go

@@ -310,6 +310,13 @@ type ddlDiff struct {
 	// exist when the view body is parsed (issue #414).
 	deferredAddedViews             []*ir.View
 	functionsAwaitingDeferredViews []*ir.Function
+	// Added functions whose return/parameter type references a view being recreated
+	// (DROP + CREATE) by this migration. For a function whose signature changed, its
+	// old definition is dropped in the drop phase; creating the new one in the create
+	// phase (before the view's DROP) would re-pin the old view and block its RESTRICT
+	// drop. They are created in the modify phase, AFTER generateModifyViewsSQL
+	// recreates the view (issue #480).
+	functionsAwaitingRecreatedViews []*ir.Function
 	// Foreign keys that depend on a unique/PK constraint being dropped or
 	// recreated by this migration: existing ones are dropped before the table
 	// modifications (fkPreDrops) and desired-state ones are (re)created
@@ -1820,6 +1827,29 @@ func (d *ddlDiff) generateCreateSQL(targetSchema string, collector *diffCollecto
 		}
 	}
 
+	// Functions whose return/parameter type references a view being recreated
+	// (DROP + CREATE in the modify phase) must be created AFTER that recreation.
+	// For a signature-changed function the old definition was dropped in the drop
+	// phase; creating the new one now (before the view's DROP) would re-pin the old
+	// view and block its RESTRICT drop (issue #480). Pull them out of both buckets
+	// and defer to the modify phase.
+	recreatedViewLookup := buildRecreatedViewLookup(d.modifiedViews)
+	if len(recreatedViewLookup) > 0 {
+		deferRecreated := func(fns []*ir.Function) []*ir.Function {
+			var keep []*ir.Function
+			for _, fn := range fns {
+				if functionReferencesNewView(fn, recreatedViewLookup) {
+					d.functionsAwaitingRecreatedViews = append(d.functionsAwaitingRecreatedViews, fn)
+				} else {
+					keep = append(keep, fn)
+				}
+			}
+			return keep
+		}
+		functionsWithoutViewDeps = deferRecreated(functionsWithoutViewDeps)
+		functionsWithViewDeps = deferRecreated(functionsWithViewDeps)
+	}
+
 	// Create functions WITHOUT view dependencies (functions may depend on tables created above)
 	generateCreateFunctionsSQL(functionsWithoutViewDeps, targetSchema, collector)
 
@@ -1982,6 +2012,14 @@ func (d *ddlDiff) generateModifySQL(targetSchema string, collector *diffCollecto
 	// Modify views - pass preDroppedViews to skip DROP for already-dropped views
 	generateModifyViewsSQL(d.modifiedViews, targetSchema, collector, preDroppedViews, dependentViewsCtx, recreatedViews)
 
+	// Create functions deferred from generateCreateSQL because their return/parameter
+	// type references a view just recreated above. Emitting them now (rather than in
+	// the create phase) keeps the recreated view free of dependents during its
+	// RESTRICT drop (issue #480).
+	if len(d.functionsAwaitingRecreatedViews) > 0 {
+		generateCreateFunctionsSQL(d.functionsAwaitingRecreatedViews, targetSchema, collector)
+	}
+
 	// Modify functions
 	generateModifyFunctionsSQL(d.modifiedFunctions, targetSchema, collector)
 
@@ -2269,6 +2307,19 @@ func buildViewLookup(views []*ir.View) map[string]struct{} {
 	return buildSchemaNameLookup(names)
 }
 
+// buildRecreatedViewLookup returns case-insensitive lookup keys for views being
+// recreated (DROP + CREATE) by this migration, i.e. modified views with
+// RequiresRecreate set.
+func buildRecreatedViewLookup(modifiedViews []*viewDiff) map[string]struct{} {
+	var names []struct{ schema, name string }
+	for _, vd := range modifiedViews {
+		if vd.RequiresRecreate {
+			names = append(names, struct{ schema, name string }{vd.New.Schema, vd.New.Name})
+		}
+	}
+	return buildSchemaNameLookup(names)
+}
+
 // functionReferencesNewView determines if a function references any newly added views
 // in its return type or parameter types. This handles cases where functions use
 // view composite types (e.g., RETURNS SETOF view_name or parameter of view_name type).

testdata/diff/dependency/issue_480_view_function_recreate/diff.sql

@@ -0,0 +1,32 @@
+DROP FUNCTION IF EXISTS fn_create_user(text);
+
+ALTER TABLE tb_users ADD COLUMN role text DEFAULT 'member' NOT NULL;
+
+DROP VIEW IF EXISTS vw_users RESTRICT;
+
+CREATE OR REPLACE VIEW vw_users AS
+ SELECT id,
+    email,
+    role,
+    created_at
+   FROM tb_users
+  WHERE is_deleted = false;
+
+CREATE OR REPLACE FUNCTION fn_create_user(
+    email text,
+    role text DEFAULT 'member'
+)
+RETURNS vw_users
+LANGUAGE plpgsql
+VOLATILE
+SECURITY DEFINER
+AS $$
+DECLARE
+    v_result vw_users;
+    v_new_id UUID;
+BEGIN
+    INSERT INTO tb_users (email, role) VALUES (email, role) RETURNING id INTO v_new_id;
+    SELECT id, email, role, created_at INTO v_result FROM vw_users WHERE id = v_new_id;
+    RETURN v_result;
+END;
+$$;

testdata/diff/dependency/issue_480_view_function_recreate/new.sql

@@ -0,0 +1,25 @@
+CREATE TABLE tb_users (
+    id uuid DEFAULT gen_random_uuid(),
+    is_deleted boolean DEFAULT false NOT NULL,
+    created_at timestamptz DEFAULT now(),
+    email text DEFAULT 'missing@missing.com' NOT NULL,
+    role text DEFAULT 'member' NOT NULL,
+    CONSTRAINT tb_users_pkey PRIMARY KEY (id)
+);
+
+CREATE VIEW vw_users AS
+SELECT id, email, role, created_at
+FROM tb_users
+WHERE is_deleted = FALSE;
+
+CREATE FUNCTION fn_create_user(email TEXT, role TEXT DEFAULT 'member')
+RETURNS vw_users AS $$
+DECLARE
+    v_result vw_users;
+    v_new_id UUID;
+BEGIN
+    INSERT INTO tb_users (email, role) VALUES (email, role) RETURNING id INTO v_new_id;
+    SELECT id, email, role, created_at INTO v_result FROM vw_users WHERE id = v_new_id;
+    RETURN v_result;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;

testdata/diff/dependency/issue_480_view_function_recreate/old.sql

@@ -0,0 +1,24 @@
+CREATE TABLE tb_users (
+    id uuid DEFAULT gen_random_uuid(),
+    is_deleted boolean DEFAULT false NOT NULL,
+    created_at timestamptz DEFAULT now(),
+    email text DEFAULT 'missing@missing.com' NOT NULL,
+    CONSTRAINT tb_users_pkey PRIMARY KEY (id)
+);
+
+CREATE VIEW vw_users AS
+SELECT id, email, created_at
+FROM tb_users
+WHERE is_deleted = FALSE;
+
+CREATE FUNCTION fn_create_user(email TEXT)
+RETURNS vw_users AS $$
+DECLARE
+    v_result vw_users;
+    v_new_id UUID;
+BEGIN
+    INSERT INTO tb_users (email) VALUES (email) RETURNING id INTO v_new_id;
+    SELECT id, email, created_at INTO v_result FROM vw_users WHERE id = v_new_id;
+    RETURN v_result;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;

testdata/diff/dependency/issue_480_view_function_recreate/plan.json

@@ -0,0 +1,44 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.11.0",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "c7ede31c4d93f537192a343c3b52ae33b76c573082ad077bfd20a09419482c9d"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "DROP FUNCTION IF EXISTS fn_create_user(text);",
+          "type": "function",
+          "operation": "drop",
+          "path": "public.fn_create_user"
+        },
+        {
+          "sql": "ALTER TABLE tb_users ADD COLUMN role text DEFAULT 'member' NOT NULL;",
+          "type": "table.column",
+          "operation": "create",
+          "path": "public.tb_users.role"
+        },
+        {
+          "sql": "DROP VIEW IF EXISTS vw_users RESTRICT;",
+          "type": "view",
+          "operation": "alter",
+          "path": "public.vw_users"
+        },
+        {
+          "sql": "CREATE OR REPLACE VIEW vw_users AS\n SELECT id,\n    email,\n    role,\n    created_at\n   FROM tb_users\n  WHERE is_deleted = false;",
+          "type": "view",
+          "operation": "alter",
+          "path": "public.vw_users"
+        },
+        {
+          "sql": "CREATE OR REPLACE FUNCTION fn_create_user(\n    email text,\n    role text DEFAULT 'member'\n)\nRETURNS vw_users\nLANGUAGE plpgsql\nVOLATILE\nSECURITY DEFINER\nAS $$\nDECLARE\n    v_result vw_users;\n    v_new_id UUID;\nBEGIN\n    INSERT INTO tb_users (email, role) VALUES (email, role) RETURNING id INTO v_new_id;\n    SELECT id, email, role, created_at INTO v_result FROM vw_users WHERE id = v_new_id;\n    RETURN v_result;\nEND;\n$$;",
+          "type": "function",
+          "operation": "create",
+          "path": "public.fn_create_user"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/dependency/issue_480_view_function_recreate/plan.sql

@@ -0,0 +1,32 @@
+DROP FUNCTION IF EXISTS fn_create_user(text);
+
+ALTER TABLE tb_users ADD COLUMN role text DEFAULT 'member' NOT NULL;
+
+DROP VIEW IF EXISTS vw_users RESTRICT;
+
+CREATE OR REPLACE VIEW vw_users AS
+ SELECT id,
+    email,
+    role,
+    created_at
+   FROM tb_users
+  WHERE is_deleted = false;
+
+CREATE OR REPLACE FUNCTION fn_create_user(
+    email text,
+    role text DEFAULT 'member'
+)
+RETURNS vw_users
+LANGUAGE plpgsql
+VOLATILE
+SECURITY DEFINER
+AS $$
+DECLARE
+    v_result vw_users;
+    v_new_id UUID;
+BEGIN
+    INSERT INTO tb_users (email, role) VALUES (email, role) RETURNING id INTO v_new_id;
+    SELECT id, email, role, created_at INTO v_result FROM vw_users WHERE id = v_new_id;
+    RETURN v_result;
+END;
+$$;

testdata/diff/dependency/issue_480_view_function_recreate/plan.txt

@@ -0,0 +1,53 @@
+Plan: 1 to add, 2 to modify, 1 to drop.
+
+Summary by type:
+  functions: 1 to add, 1 to drop
+  tables: 1 to modify
+  views: 1 to modify
+
+Functions:
+  - fn_create_user
+  + fn_create_user
+
+Tables:
+  ~ tb_users
+    + role (column)
+
+Views:
+  ~ vw_users
+
+DDL to be executed:
+--------------------------------------------------
+
+DROP FUNCTION IF EXISTS fn_create_user(text);
+
+ALTER TABLE tb_users ADD COLUMN role text DEFAULT 'member' NOT NULL;
+
+DROP VIEW IF EXISTS vw_users RESTRICT;
+
+CREATE OR REPLACE VIEW vw_users AS
+ SELECT id,
+    email,
+    role,
+    created_at
+   FROM tb_users
+  WHERE is_deleted = false;
+
+CREATE OR REPLACE FUNCTION fn_create_user(
+    email text,
+    role text DEFAULT 'member'
+)
+RETURNS vw_users
+LANGUAGE plpgsql
+VOLATILE
+SECURITY DEFINER
+AS $$
+DECLARE
+    v_result vw_users;
+    v_new_id UUID;
+BEGIN
+    INSERT INTO tb_users (email, role) VALUES (email, role) RETURNING id INTO v_new_id;
+    SELECT id, email, role, created_at INTO v_result FROM vw_users WHERE id = v_new_id;
+    RETURN v_result;
+END;
+$$;