Add config migration

Author: kardolus

config/store.go

@@ -11,7 +11,7 @@ import (
 const (
 	openAIName             = "openai"
 	openAIModel            = "gpt-3.5-turbo"
-	openAIModelMaxTokens   = 4096
+	openAIMaxTokens        = 4096
 	openAIContextWindow    = 8192
 	openAIURL              = "https://api.openai.com"
 	openAICompletionsPath  = "/v1/chat/completions"
@@ -77,15 +77,20 @@ func (f *FileIO) List() ([]string, error) {
 }
 
 func (f *FileIO) Read() (types.Config, error) {
-	return parseFile(f.configFilePath)
+	result, err := parseFile(f.configFilePath)
+	if err != nil {
+		return types.Config{}, err
+	}
+
+	return migrate(result), nil
 }
 
 func (f *FileIO) ReadDefaults() types.Config {
 	return types.Config{
 		Name:             openAIName,
 		Model:            openAIModel,
 		Role:             openAIRole,
-		MaxTokens:        openAIModelMaxTokens,
+		MaxTokens:        openAIMaxTokens,
 		ContextWindow:    openAIContextWindow,
 		URL:              openAIURL,
 		CompletionsPath:  openAICompletionsPath,
@@ -118,6 +123,19 @@ func getPath() (string, error) {
 	return filepath.Join(homeDir, "config.yaml"), nil
 }
 
+func migrate(config types.Config) types.Config {
+	// the "old" max_tokens became context_window
+	if config.ContextWindow == 0 && config.MaxTokens > 0 {
+		config.ContextWindow = config.MaxTokens
+		// set it to the default in case the value is small
+		if config.ContextWindow < openAIContextWindow {
+			config.ContextWindow = openAIContextWindow
+		}
+		config.MaxTokens = openAIMaxTokens
+	}
+	return config
+}
+
 func parseFile(fileName string) (types.Config, error) {
 	var result types.Config
 

integration/integration_test.go

@@ -141,13 +141,49 @@ func testIntegration(t *testing.T, when spec.G, it spec.S) {
 			Expect(err).NotTo(HaveOccurred())
 		})
 
-		it("reads the config from the file", func() {
-			err = configIO.Write(testConfig) // need to write before reading
-			Expect(err).NotTo(HaveOccurred())
+		when("reading the config from a file", func() {
+			defaults := config.New().ReadDefaults()
 
-			readConfig, err := configIO.Read()
-			Expect(err).NotTo(HaveOccurred())
-			Expect(readConfig).To(Equal(testConfig))
+			it("it doesn't apply a migration when max_tokens is 0", func() {
+				testConfig.MaxTokens = 0
+
+				err = configIO.Write(testConfig) // need to write before reading
+				Expect(err).NotTo(HaveOccurred())
+
+				readConfig, err := configIO.Read()
+				Expect(err).NotTo(HaveOccurred())
+				Expect(readConfig).To(Equal(testConfig))
+			})
+			it("it migrates small values of max_tokens as expected", func() {
+				testConfig.MaxTokens = defaults.ContextWindow - 1
+
+				err = configIO.Write(testConfig) // need to write before reading
+				Expect(err).NotTo(HaveOccurred())
+
+				readConfig, err := configIO.Read()
+				Expect(err).NotTo(HaveOccurred())
+
+				expectedConfig := testConfig
+				expectedConfig.MaxTokens = defaults.MaxTokens
+				expectedConfig.ContextWindow = defaults.ContextWindow
+
+				Expect(readConfig).To(Equal(expectedConfig))
+			})
+			it("it migrates large values of max_tokens as expected", func() {
+				testConfig.MaxTokens = defaults.ContextWindow + 1
+
+				err = configIO.Write(testConfig) // need to write before reading
+				Expect(err).NotTo(HaveOccurred())
+
+				readConfig, err := configIO.Read()
+				Expect(err).NotTo(HaveOccurred())
+
+				expectedConfig := testConfig
+				expectedConfig.MaxTokens = defaults.MaxTokens
+				expectedConfig.ContextWindow = testConfig.MaxTokens
+
+				Expect(readConfig).To(Equal(expectedConfig))
+			})
 		})
 
 		it("lists all the threads", func() {