Add enum support

internal/migration_acceptance_tests/enum_cases_test.go

@@ -0,0 +1,131 @@
+package migration_acceptance_tests
+
+import "github.com/stripe/pg-schema-diff/pkg/diff"
+
+var enumAcceptanceTestCases = []acceptanceTestCase{
+	{
+		name: "no-op",
+		oldSchemaDDL: []string{
+			`
+			CREATE TYPE color AS ENUM ('red', 'green', 'blue');
+			CREATE TABLE foo(
+				color color DEFAULT 'green'
+			);
+			`,
+		},
+		newSchemaDDL: []string{
+			`
+			CREATE TYPE color AS ENUM ('red', 'green', 'blue');
+			CREATE TABLE foo(
+				color color DEFAULT 'green'
+			);
+			`,
+		},
+
+		vanillaExpectations: expectations{
+			empty: true,
+		},
+		dataPackingExpectations: expectations{
+			empty: true,
+		},
+	},
+	{
+		name: "create enum",
+		oldSchemaDDL: []string{
+			`
+			CREATE TABLE foo();
+			`,
+		},
+		newSchemaDDL: []string{
+			`
+			CREATE SCHEMA schema_1;
+			CREATE TYPE schema_1.color AS ENUM ('red', 'green', 'blue');
+			CREATE TABLE foo(
+				color schema_1.color DEFAULT 'green'
+			);
+			`,
+		},
+	},
+	{
+		name: "drop enum",
+		oldSchemaDDL: []string{
+			`
+			CREATE SCHEMA schema_1;
+			CREATE TYPE schema_1.color AS ENUM ('red', 'green', 'blue');
+			CREATE TABLE foo(
+				color schema_1.color DEFAULT 'green'
+			);
+			`,
+		},
+		newSchemaDDL: []string{
+			`
+			CREATE SCHEMA schema_1;
+			CREATE TABLE foo(
+			    color VARCHAR(255) DEFAULT 'green'
+			);
+			`,
+		},
+		expectedHazardTypes: []diff.MigrationHazardType{
+			diff.MigrationHazardTypeAcquiresAccessExclusiveLock,
+			diff.MigrationHazardTypeImpactsDatabasePerformance,
+		},
+	},
+	{
+		name: "add values",
+		oldSchemaDDL: []string{
+			`
+			CREATE TYPE some_enum_1 AS ENUM ('1', '2', '3');
+			CREATE TABLE foo(
+				val some_enum_1
+			);
+		`},
+		newSchemaDDL: []string{
+			`
+			CREATE TYPE some_enum_1 AS ENUM ('0', '1', '1.5', '2', '2.5', '3', '4');
+			CREATE TABLE foo(
+				val some_enum_1 DEFAULT '1.5'
+			);
+		`},
+	},
+	{
+		name: "delete value and add value (enum not used)",
+		oldSchemaDDL: []string{
+			`
+			CREATE TYPE some_enum_1 AS ENUM ('1', '2', '3');
+		`},
+		newSchemaDDL: []string{
+			`
+			CREATE TYPE some_enum_1 AS ENUM ('0', '1', '3');
+		`},
+	},
+	{
+		name: "delete value and add value (enum used)",
+		oldSchemaDDL: []string{
+			`
+			CREATE TYPE some_enum_1 AS ENUM ('1', '2', '3');
+			CREATE TABLE foo(
+				val some_enum_1
+			);
+		`},
+		newSchemaDDL: []string{
+			`
+			CREATE TYPE some_enum_1 AS ENUM ('0', '1', '3');
+			CREATE TABLE foo(
+				val some_enum_1
+			);
+		`},
+
+		// Removing a value from an enum in-use is impossible in Postgres. pg-schema-diff will currently identify this
+		// as a validation error. In the future, we can identify this in the actual plan generation stage.
+		vanillaExpectations: expectations{
+			planErrorContains: errValidatingPlan.Error(),
+		},
+		dataPackingExpectations: expectations{
+			planErrorContains: errValidatingPlan.Error(),
+		},
+	},
+}
+
+func (s *acceptanceTestSuite) TestEnumTestCases() {
+	s.runTestCases(enumAcceptanceTestCases)
+}

internal/migration_acceptance_tests/schema_cases_test.go

@@ -16,6 +16,8 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 			CREATE TABLE fizz(
 			);
 
+			CREATE TYPE schema_1.color AS ENUM ('red', 'green', 'blue');
+
 			CREATE SEQUENCE schema_1.foobar_sequence
 			    AS BIGINT
 				INCREMENT BY 2
@@ -46,6 +48,7 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 				foo VARCHAR(255) DEFAULT 'some default' NOT NULL CHECK (LENGTH(foo) > 0),
 			    bar SERIAL NOT NULL,
 			    fizz TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+				color schema_1.color DEFAULT 'green',
 			    PRIMARY KEY (foo, id),
 				UNIQUE (foo, bar)
 			) PARTITION BY LIST(foo);
@@ -83,6 +86,8 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 			CREATE TABLE fizz(
 			);
 
+			CREATE TYPE schema_1.color AS ENUM ('red', 'green', 'blue');
+
 			CREATE SEQUENCE schema_1.foobar_sequence
 			    AS BIGINT
 				INCREMENT BY 2
@@ -113,6 +118,7 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 				foo VARCHAR(255) DEFAULT 'some default' NOT NULL CHECK (LENGTH(foo) > 0),
 			    bar SERIAL NOT NULL,
 			    fizz TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+				color schema_1.color DEFAULT 'green',
 			    PRIMARY KEY (foo, id),
 				UNIQUE (foo, bar)
 			) PARTITION BY LIST(foo);
@@ -150,7 +156,7 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 		},
 	},
 	{
-		name: "Add schema, drop schema, Drop table, Add Table, Drop Seq, Add Seq, Drop Funcs, Add Funcs, Drop Triggers, Add Triggers, Create Extension, Drop Extension, Create Index Using Extension",
+		name: "Add schema, drop schema, Add enum, Drop enum, Drop table, Add Table, Drop Seq, Add Seq, Drop Funcs, Add Funcs, Drop Triggers, Add Triggers, Create Extension, Drop Extension, Create Index Using Extension",
 		oldSchemaDDL: []string{
 			`
 			CREATE SCHEMA schema_1;
@@ -161,6 +167,8 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 			CREATE TABLE fizz(
 			);
 
+			CREATE TYPE schema_1.color AS ENUM ('red', 'green', 'blue');
+
 			CREATE SEQUENCE schema_2.foobar_sequence
 			    AS BIGINT
 				INCREMENT BY 2
@@ -198,6 +206,7 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 			    bar SERIAL NOT NULL,
 				foo VARCHAR(255) DEFAULT 'some default' NOT NULL,
 			    fizz TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+				color schema_1.color DEFAULT 'green',
 				UNIQUE (foo, bar)
 			);
 			CREATE INDEX foobar_normal_idx ON foobar USING hash (fizz);
@@ -233,6 +242,8 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 			CREATE TABLE fizz(
 			);
 
+			CREATE TYPE new_color AS ENUM ('yellow', 'orange', 'cyan');
+
 			CREATE SEQUENCE schema_3.new_foobar_sequence
 			    AS SMALLINT
 				INCREMENT BY 4
@@ -269,6 +280,7 @@ var schemaAcceptanceTests = []acceptanceTestCase{
 			    new_fizz TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
 			    id INT PRIMARY KEY,
 			    version INT NOT NULL DEFAULT 0,
+			    new_color new_color DEFAULT 'cyan',
 			    new_bar SMALLSERIAL NOT NULL,
 				new_foo VARCHAR(255) DEFAULT '' NOT NULL CHECK ( new_foo IS NOT NULL),
 				UNIQUE (new_foo, new_bar)

internal/queries/queries.sql

@@ -282,7 +282,7 @@ LEFT JOIN
 WHERE
     seq_ns.nspname NOT IN ('pg_catalog', 'information_schema')
     AND seq_ns.nspname !~ '^pg_toast'
-    -- It doesn't belong to an extension
+    -- Exclude sequences belonging to extensions
     AND NOT EXISTS (
         SELECT ext_depend.objid
         FROM pg_catalog.pg_depend AS ext_depend
@@ -305,3 +305,31 @@ INNER JOIN
 WHERE
     extension_namespace.nspname NOT IN ('pg_catalog', 'information_schema')
     AND extension_namespace.nspname !~ '^pg_toast';
+
+
+-- name: GetEnums :many
+SELECT
+    pg_type.typname::TEXT AS enum_name,
+    type_namespace.nspname::TEXT AS enum_schema_name,
+    (
+        SELECT ARRAY_AGG(pg_enum.enumlabel ORDER BY pg_enum.enumsortorder)
+        FROM pg_catalog.pg_enum
+        WHERE pg_enum.enumtypid = pg_type.oid
+    )::TEXT [] AS enum_labels
+FROM pg_catalog.pg_type AS pg_type
+INNER JOIN
+    pg_catalog.pg_namespace AS type_namespace
+    ON type_namespace.oid = pg_type.typnamespace
+WHERE
+    pg_type.typtype = 'e'
+    AND type_namespace.nspname NOT IN ('pg_catalog', 'information_schema')
+    AND type_namespace.nspname !~ '^pg_toast'
+    -- Exclude enums belonging to extensions
+    AND NOT EXISTS (
+        SELECT ext_depend.objid
+        FROM pg_catalog.pg_depend AS ext_depend
+        WHERE
+            ext_depend.classid = 'pg_class'::REGCLASS
+            AND ext_depend.objid = pg_type.oid
+            AND ext_depend.deptype = 'e'
+    );