Merge pull request #469 from fujiwara/fix-option-override

Make the specification clear for overriding flag priorities.

README.md

@@ -245,6 +245,12 @@ The file format is JSON or Jsonnet.
 All fields are optional. If the field is not defined, the default value is used.
 When command-line flags are specified, they take precedence over the options file.
 
+The priority of the option values is as follows:
+
+1. Command-line flags. (`--log-level=debug`)
+2. The values defined in the option file. (`{"log_level": "debug"}`)
+3. Environment variables. (`LAMBROLL_LOGLEVEL=debug`)
+
 While parsing the option file, lambroll evaluates only the `{{env}}` and `{{must_env}}` template functions and `env` and `must_env` native functions in Jsonnet. Other functions are not available.
 
 ### Init

cli_test.go

@@ -118,6 +118,43 @@ var cliTests = []struct {
 		sub:  "render",
 		err:  os.ErrNotExist,
 	},
+	{
+		args: []string{"render", "--option", "override.jsonnet",
+			"--profile", "mine",
+			"--region", "us-west-2",
+		},
+		env: map[string]string{
+			"LAMBROLL_LOG_LEVEL": "debug",
+		},
+		sub: "render",
+		option: &lambroll.Option{
+			OptionFilePath: "override.jsonnet",
+			Color:          true,
+			Envfile:        []string{},
+			LogLevel:       "trace", // option file's priority is higher than env
+			Profile:        ptr("mine"),
+			Region:         ptr("us-west-2"),
+		},
+	},
+	{
+		args: []string{"render",
+			"--profile", "mine",
+			"--region", "us-west-2",
+		},
+		env: map[string]string{
+			"LAMBROLL_OPTION":    "override.jsonnet",
+			"LAMBROLL_LOG_LEVEL": "debug",
+		},
+		sub: "render",
+		option: &lambroll.Option{
+			OptionFilePath: "override.jsonnet",
+			Color:          true,
+			Envfile:        []string{},
+			LogLevel:       "trace", // option file's priority is higher than env
+			Profile:        ptr("mine"),
+			Region:         ptr("us-west-2"),
+		},
+	},
 }
 
 func TestParseCLI(t *testing.T) {

lambroll_test.go

@@ -85,3 +85,7 @@ func TestFillDefaultValues(t *testing.T) {
 		})
 	}
 }
+
+func ptr[T any](v T) *T {
+	return &v
+}

test/cli/override.jsonnet

@@ -0,0 +1,5 @@
+{
+  profile: 'dummy',
+  region: 'us-east-1',
+  log_level: 'trace',
+}