Merge pull request cosmos#1603: Adding option functions to NewBaseApp

* adding option functions to baseapp constructor

* Added simple test and changed godoc

* remove unrelated changelog updates

CHANGELOG.md

@@ -21,6 +21,7 @@ BREAKING CHANGES
 * [auth] Removed MsgChangePubKey
 * [auth] Removed SetPubKey from account mapper
 * [auth] AltBytes renamed to Memo, now a string, max 100 characters, costs a bit of gas
+* [baseapp] NewBaseApp now takes option functions as parameters
 * [types] `GetMsg()` -> `GetMsgs()` as txs wrap many messages
 * [types] Removed GetMemo from Tx (it is still on StdTx)
 * [types] renamed rational.Evaluate to rational.Round{Int64, Int}

baseapp/baseapp.go

@@ -73,7 +73,8 @@ var _ abci.Application = (*BaseApp)(nil)
 
 // Create and name new BaseApp
 // NOTE: The db is used to store the version number for now.
-func NewBaseApp(name string, cdc *wire.Codec, logger log.Logger, db dbm.DB) *BaseApp {
+// Accepts variable number of option functions, which act on the BaseApp to set configuration choices
+func NewBaseApp(name string, cdc *wire.Codec, logger log.Logger, db dbm.DB, options ...func(*BaseApp)) *BaseApp {
 	app := &BaseApp{
 		Logger:     logger,
 		name:       name,
@@ -86,6 +87,9 @@ func NewBaseApp(name string, cdc *wire.Codec, logger log.Logger, db dbm.DB) *Bas
 	}
 	// Register the undefined & root codespaces, which should not be used by any modules
 	app.codespacer.RegisterOrPanic(sdk.CodespaceRoot)
+	for _, option := range options {
+		option(app)
+	}
 	return app
 }
 

baseapp/baseapp_test.go

@@ -139,6 +139,21 @@ func testLoadVersionHelper(t *testing.T, app *BaseApp, expectedHeight int64, exp
 	require.Equal(t, expectedID, lastID)
 }
 
+func TestOptionFunction(t *testing.T) {
+	logger := defaultLogger()
+	db := dbm.NewMemDB()
+	codec := wire.NewCodec()
+	registerTestCodec(codec)
+	bap := NewBaseApp("starting name", codec, logger, db, testChangeNameHelper("new name"))
+	require.Equal(t, bap.name, "new name", "BaseApp should have had name changed via option function")
+}
+
+func testChangeNameHelper(name string) func(*BaseApp) {
+	return func(bap *BaseApp) {
+		bap.name = name
+	}
+}
+
 // Test that the app hash is static
 // TODO: https://github.com/cosmos/cosmos-sdk/issues/520
 /*func TestStaticAppHash(t *testing.T) {