4 files changed, 49 insertions, 22 deletions
diff --git a/src/cmd/run.go b/src/cmd/run.go
index aeec65d..fb62f67 100644
--- a/src/cmd/run.go
+++ b/src/cmd/run.go
@@ -21,7 +21,7 @@ var cmdRun = &cobra.Command{
 		out, err := exercises.Run(args[0])
 		fmt.Println(out)
 		if err != nil {
-			color.Red("Your exercise is failing")
+			color.Red("Your exercise is failing: %s", err)
 			os.Exit(1)
 		}
 		color.Green("Congratulations!")
diff --git a/src/exercises/exercise.go b/src/exercises/exercise.go
new file mode 100644
index 0000000..2783381
--- /dev/null
+++ b/src/exercises/exercise.go
@@ -0,0 +1,20 @@
+package exercises
+
+type Exercise struct {
+	Name  string
+	Path  string
+	Mode  string
+	Hint  string
+	State State
+}
+
+type State int
+
+const (
+	Pending State = iota + 1
+	Done
+)
+
+func (s State) String() string {
+	return [...]string{"Pending", "Done"}[s-1]
+}
diff --git a/src/exercises/list.go b/src/exercises/list.go
index 3719527..c0c7261 100644
--- a/src/exercises/list.go
+++ b/src/exercises/list.go
@@ -1,29 +1,13 @@
 package exercises
 
 import (
+	"errors"
 	"os"
 
 	"github.com/pelletier/go-toml/v2"
 )
 
-type State int
-
-const (
-	Pending State = iota + 1
-	Done
-)
-
-func (s State) String() string {
-	return [...]string{"Pending", "Done"}[s-1]
-}
-
-type Exercise struct {
-	Name  string
-	Path  string
-	Mode  string
-	Hint  string
-	State State
-}
+var ErrExerciseNotFound = errors.New("exercise not found")
 
 type Info struct {
 	Exercises []Exercise
@@ -43,3 +27,18 @@ func List() ([]Exercise, error) {
 
 	return info.Exercises, nil
 }
+
+func Find(exercise string) (Exercise, error) {
+	exs, err := List()
+	if err != nil {
+		return Exercise{}, err
+	}
+
+	for _, ex := range exs {
+		if ex.Name == exercise {
+			return ex, nil
+		}
+	}
+
+	return Exercise{}, ErrExerciseNotFound
+}
diff --git a/src/exercises/runner.go b/src/exercises/runner.go
index 1fe2a32..1490f13 100644
--- a/src/exercises/runner.go
+++ b/src/exercises/runner.go
@@ -1,9 +1,17 @@
 package exercises
 
-import "os/exec"
+import (
+	"fmt"
+	"os/exec"
+)
 
-func Run(exercise string) (string, error) {
-	cmd := exec.Command("go", "run", "./exercises/"+exercise+".go")
+func Run(name string) (string, error) {
+	exercise, err := Find(name)
+	if err != nil {
+		return "", err
+	}
+
+	cmd := exec.Command("go", "run", fmt.Sprintf("./%s", exercise.Path))
 	cOut, err := cmd.CombinedOutput()
 	return string(cOut), err
 }