feat: solve day 1 part 1

cmd/01/instruction/instruction.go

@@ -0,0 +1,40 @@
+// Package instruction provides a model for representing dial instructions
+package instruction
+
+import "strconv"
+
+type Instruction interface {
+	Direction() string
+	Distance() int
+}
+
+type instruction struct {
+	direction string
+	distance  int
+}
+
+func FromLine(line string) Instruction {
+	dir := string(line[0])
+	dist := line[1:]
+	distAsInt, _ := strconv.Atoi(dist)
+
+	return instruction{
+		direction: dir,
+		distance:  distAsInt,
+	}
+}
+
+func FromParts(direction string, distance int) Instruction {
+	return instruction{
+		direction: direction,
+		distance:  distance,
+	}
+}
+
+func (i instruction) Direction() string {
+	return i.direction
+}
+
+func (i instruction) Distance() int {
+	return i.distance
+}

cmd/01/instruction/instruction_test.go

@@ -0,0 +1,39 @@
+package instruction_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/StevanFreeborn/advent-of-code-2025/cmd/01/instruction"
+)
+
+func TestFromLine(t *testing.T) {
+	expectedDirection := "L"
+	expectedDistance := 7
+	line := fmt.Sprintf("%s%d", expectedDirection, expectedDistance)
+
+	result := instruction.FromLine(line)
+
+	if result.Direction() != expectedDirection {
+		t.Errorf("got direction %s but expected direction %s", result.Direction(), expectedDirection)
+	}
+
+	if result.Distance() != expectedDistance {
+		t.Errorf("got distance %d but expected distance %d", result.Distance(), expectedDistance)
+	}
+}
+
+func TestFromParts(t *testing.T) {
+	expectedDirection := "L"
+	expectedDistance := 7
+
+	result := instruction.FromParts(expectedDirection, expectedDistance)
+
+	if result.Direction() != expectedDirection {
+		t.Errorf("got direction %s but expected direction %s", result.Direction(), expectedDirection)
+	}
+
+	if result.Distance() != expectedDistance {
+		t.Errorf("got distance %d but expected distance %d", result.Distance(), expectedDistance)
+	}
+}