Add abitlity to partially override config from submodules

khos2ow · khos2ow · commit 6f97f6767e2c · 2021-09-30T18:53:13.000-04:00
In the original implementation, when a submodule provided its
configuration it would completely override any config was provided by
its parent module. However with this approach the child module's
configuration will merge into its parent config and override any item
defined by both.

Example:

```
$ cat .terraform-docs.yml
formatter: markdown table
recursive:
  enabled: true
sections:
  show:
    - header
    - inputs
    - outputs
output:
  file: README.md
  mode: inject
settings:
  default: true
  required: true
  type: true

$ cat modules/module-b/.terraform-docs.yml
formatter: yaml
sections:
  show:
    - providers
settings:
  default: false
  escape: false
```

The computed values for module-b configuration will be:

```
formatter: yaml
recursive:
  enabled: true
sections:
  show:
    - providers
output:
  file: README.md
  mode: inject
settings:
  default: false
  escape: false
  required: true
  type: true
```

Signed-off-by: Khosrow Moossavi &lt;khos2ow@gmail.com&gt;
diff --git a/internal/cli/run.go b/internal/cli/run.go
@@ -71,8 +71,15 @@ func (r *Runtime) PreRunEFunc(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("value of '--config' can't be empty")
 	}
 
-	// attempt to read config file and override them with corresponding flags
-	if err := r.readConfig(r.config, ""); err != nil {
+	// read config file and override them with corresponding flags
+	v := viper.New()
+
+	if err := r.readConfig(v, r.config.File, ""); err != nil {
+		return err
+	}
+
+	// and override them with corresponding flags
+	if err := r.unmarshalConfig(v, r.config); err != nil {
 		return err
 	}
 
@@ -135,11 +142,9 @@ func (r *Runtime) RunEFunc(cmd *cobra.Command, args []string) error {
 // readConfig attempts to read config file, either default `.terraform-docs.yml`
 // or provided file with `-c, --config` flag. It will then attempt to override
 // them with corresponding flags (if set).
-func (r *Runtime) readConfig(config *print.Config, submoduleDir string) error {
-	v := viper.New()
-
+func (r *Runtime) readConfig(v *viper.Viper, file string, submoduleDir string) error {
 	if r.isFlagChanged("config") {
-		v.SetConfigFile(config.File)
+		v.SetConfigFile(file)
 	} else {
 		v.SetConfigName(".terraform-docs")
 		v.SetConfigType("yml")
@@ -159,7 +164,7 @@ func (r *Runtime) readConfig(config *print.Config, submoduleDir string) error {
 	if err := v.ReadInConfig(); err != nil {
 		var perr *os.PathError
 		if errors.As(err, &perr) {
-			return fmt.Errorf("config file %s not found", config.File)
+			return fmt.Errorf("config file %s not found", file)
 		}
 
 		var cerr viper.ConfigFileNotFoundError
@@ -174,6 +179,10 @@ func (r *Runtime) readConfig(config *print.Config, submoduleDir string) error {
 		}
 	}
 
+	return nil
+}
+
+func (r *Runtime) unmarshalConfig(v *viper.Viper, config *print.Config) error {
 	r.bindFlags(v)
 
 	if err := v.Unmarshal(config); err != nil {
@@ -188,7 +197,6 @@ func (r *Runtime) readConfig(config *print.Config, submoduleDir string) error {
 		config.Formatter = r.formatter
 	}
 
-	// TODO
 	config.Parse()
 
 	return nil
@@ -229,6 +237,22 @@ func (r *Runtime) bindFlags(v *viper.Viper) {
 	})
 }
 
+func (r *Runtime) mergeConfig(v *viper.Viper) (*print.Config, error) {
+	copy := *r.config
+	merged := &copy
+
+	if v.IsSet("sections.show") || v.IsSet("sections.hide") {
+		merged.Sections.Show = []string{}
+		merged.Sections.Hide = []string{}
+	}
+
+	if err := r.unmarshalConfig(v, merged); err != nil {
+		return nil, err
+	}
+
+	return merged, nil
+}
+
 // findSubmodules generates list of submodules in `rootDir/RecursivePath` if
 // `--recursive` flag is set. This keeps track of `.terraform-docs.yml` in any
 // of the submodules (if exists) to override the root configuration.
@@ -257,9 +281,13 @@ func (r *Runtime) findSubmodules() ([]module, error) {
 		cfgfile := filepath.Join(path, r.config.File)
 
 		if _, err := os.Stat(cfgfile); !os.IsNotExist(err) {
-			cfg = print.DefaultConfig()
+			v := viper.New()
+
+			if err = r.readConfig(v, cfgfile, path); err != nil {
+				return nil, err
+			}
 
-			if err := r.readConfig(cfg, path); err != nil {
+			if cfg, err = r.mergeConfig(v); err != nil {
 				return nil, err
 			}
 		}
