Refactor Sudoku field and solver implementation

sudoku/sudoku_test.go

@@ -0,0 +1,65 @@
+package sudoku
+
+import (
+	"crypto/sha1"
+	"errors"
+	"fmt"
+	"testing"
+
+	"git.kleiax.de/homepage/logic"
+	"git.kleiax.de/homepage/logic/strategies"
+	"git.kleiax.de/homepage/parser"
+)
+
+const solvedSudoku = "123456789456789123789123456234567891567891234891234567345678912678912345912345678"
+
+func puzzleBankRecord(digits string, rating float64) string {
+	hash := fmt.Sprintf("%x", sha1.Sum([]byte(digits)))[:12]
+	return fmt.Sprintf("%s %s   %.1f", hash, digits, rating)
+}
+
+func TestNewSelectsExplicitPuzzleIndex(t *testing.T) {
+	data := puzzleBankRecord("0"+solvedSudoku[1:], 1.0) + "\n" + puzzleBankRecord(solvedSudoku, 2.0)
+	game, err := New(&parser.PuzzleBank{}, logic.Solver{}, []byte(data), 1)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+	if game.GetField().GetRating() != 2 || !game.GetField().IsSolved() {
+		t.Fatal("New() did not select puzzle index 1")
+	}
+}
+
+func TestNewRejectsInvalidIndexAndInput(t *testing.T) {
+	valid := puzzleBankRecord(solvedSudoku, 1.0)
+	if _, err := New(&parser.PuzzleBank{}, logic.Solver{}, []byte(valid), 1); !errors.Is(err, parser.ErrFieldIndex) {
+		t.Fatalf("index error = %v, want ErrFieldIndex", err)
+	}
+	if _, err := New(&parser.PuzzleString{}, logic.Solver{}, []byte("invalid"), 0); err == nil {
+		t.Fatal("invalid input error = nil")
+	}
+}
+
+func TestSolveCompletesSimplePuzzle(t *testing.T) {
+	solver := logic.Solver{}
+	solver.Add(&strategies.LastDigit{})
+	game, err := New(&parser.PuzzleString{}, solver, []byte("0"+solvedSudoku[1:]), 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := game.Solve(); err != nil {
+		t.Fatalf("Solve() error = %v", err)
+	}
+	if !game.GetField().IsSolved() {
+		t.Fatal("field is not solved")
+	}
+}
+
+func TestSolveReportsNoProgress(t *testing.T) {
+	game, err := New(&parser.PuzzleString{}, logic.Solver{}, []byte("0"+solvedSudoku[1:]), 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := game.Solve(); !errors.Is(err, logic.ErrNoProgress) {
+		t.Fatalf("Solve() error = %v, want ErrNoProgress", err)
+	}
+}