refactor(config): resolve from the source schema, drop viper from course loading

cmd/config.go

@@ -3,7 +3,6 @@ package cmd
 import (
 	"fmt"
 	"os"
-	"path/filepath"
 
 	"github.com/logrusorgru/aurora/v4"
 	"github.com/obcode/glabs/v2/config"
@@ -45,7 +44,10 @@ it can gate a commit hook or CI.`,
 	Run: func(cmd *cobra.Command, args []string) {
 		problems := 0
 		for _, course := range coursesToProcess(args) {
-			path := courseFilePath(course)
+			path, err := findCourseFile(course)
+			if err != nil {
+				er(err)
+			}
 			source, decoded, err := decodeCourseFile(path)
 			if err != nil {
 				er(err)
@@ -86,7 +88,7 @@ parsed configuration, not edited in place. Review the diff before committing.`,
 	Args: cobra.MinimumNArgs(1),
 	Run: func(cmd *cobra.Command, args []string) {
 		for _, course := range args {
-			rewriteCourseFile(courseFilePath(course))
+			rewriteCourseFile(course)
 		}
 	},
 }
@@ -109,12 +111,17 @@ Comments and key order are not preserved. Review the diff before committing.`,
 	Args: cobra.MinimumNArgs(1),
 	Run: func(cmd *cobra.Command, args []string) {
 		for _, course := range args {
-			rewriteCourseFile(courseFilePath(course))
+			rewriteCourseFile(course)
 		}
 	},
 }
 
-func rewriteCourseFile(path string) {
+func rewriteCourseFile(course string) {
+	path, err := findCourseFile(course)
+	if err != nil {
+		er(err)
+	}
+
 	source, _, err := decodeCourseFile(path)
 	if err != nil {
 		er(err)
@@ -164,18 +171,3 @@ func coursesToProcess(args []string) []string {
 	}
 	return courses
 }
-
-// courseFilePath locates a course file the same way initConfig does: by name,
-// under coursesfilepath, with the extensions viper would have accepted.
-func courseFilePath(course string) string {
-	dir := viper.GetString("coursesfilepath")
-	for _, ext := range []string{".yaml", ".yml"} {
-		path := filepath.Join(dir, course+ext)
-		if _, err := os.Stat(path); err == nil {
-			return path
-		}
-	}
-	er(fmt.Sprintf("cannot find a course file for %q: looked for %s.yaml and %s.yml in %q",
-		course, course, course, dir))
-	return ""
-}

cmd/root.go

@@ -3,9 +3,11 @@ package cmd
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/mitchellh/go-homedir"
+	"github.com/obcode/glabs/v2/config"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 	"github.com/spf13/cobra"
@@ -68,16 +70,36 @@ func initConfig() {
 
 	viper.AutomaticEnv()
 
-	if err := viper.ReadInConfig(); err == nil {
-		viper.AddConfigPath(viper.GetString("coursesfilepath"))
-		for _, course := range viper.GetStringSlice("courses") {
-			viper.SetConfigName(course)
-			err = viper.MergeInConfig()
-			if err != nil {
-				panic(fmt.Errorf("%s: should be %s.yml", err, course))
-			}
+	if err := viper.ReadInConfig(); err != nil {
+		er(fmt.Errorf("cannot read the main config file: %w", err))
+	}
+
+	// Course files are loaded into config's own registry rather than merged into
+	// viper. Merging them put course names in the same flat namespace as
+	// gitlab.host and coursesfilepath — a course named `courses` would have
+	// collided with the course list — and left resolution reading, and writing,
+	// global state.
+	for _, course := range viper.GetStringSlice("courses") {
+		path, err := findCourseFile(course)
+		if err != nil {
+			er(err)
+		}
+		if _, err := config.LoadCourseFile(path); err != nil {
+			er(err)
+		}
+	}
+}
+
+// findCourseFile locates a course file by name under coursesfilepath, accepting
+// the extensions viper used to search for.
+func findCourseFile(course string) (string, error) {
+	dir := viper.GetString("coursesfilepath")
+	for _, ext := range []string{".yaml", ".yml"} {
+		path := filepath.Join(dir, course+ext)
+		if _, err := os.Stat(path); err == nil {
+			return path, nil
 		}
-	} else {
-		panic(fmt.Errorf("fatal error config file: %s", err))
 	}
+	return "", fmt.Errorf("cannot find a course file for %q: looked for %s.yaml and %s.yml in %q",
+		course, course, course, dir)
 }