puzzles: Add Solver tests

Author: obalunenko

puzzles/solver.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"sort"
 	"sync"
+	"testing"
 
 	"github.com/pkg/errors"
 )
@@ -41,6 +42,18 @@ func Register(name string, solver Solver) {
 	solvers[name] = solver
 }
 
+// UnregisterAllSolvers cleans up registered solvers. Use for testing only.
+func UnregisterAllSolvers(tb testing.TB) {
+	if tb == nil {
+		panic("could not be called outside of tests")
+	}
+
+	solversMu.Lock()
+	defer solversMu.Unlock()
+
+	solvers = make(map[string]Solver)
+}
+
 // Solvers returns a sorted list of the names of the registered puzzle solvers.
 func Solvers() []string {
 	solversMu.RLock()

puzzles/solver_test.go

@@ -0,0 +1,78 @@
+package puzzles_test
+
+import (
+	"fmt"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/oleg-balunenko/advent-of-code/puzzles"
+)
+
+type mockSolver struct{}
+
+func (m mockSolver) Part1(input io.Reader) (string, error) {
+	return fmt.Sprint("part 1 of mockSolver"), nil
+}
+
+func (m mockSolver) Part2(input io.Reader) (string, error) {
+	return fmt.Sprint("part 2 of mockSolver"), nil
+}
+
+func (m mockSolver) Name() string {
+	return "mockSolver"
+}
+
+type anotherMockSolver struct{}
+
+func (a anotherMockSolver) Part1(input io.Reader) (string, error) {
+	return fmt.Sprint("part 1 of anotherMockSolver"), nil
+}
+
+func (a anotherMockSolver) Part2(input io.Reader) (string, error) {
+	return fmt.Sprint("part 2 of anotherMockSolver"), nil
+}
+
+func (a anotherMockSolver) Name() string {
+	return "anotherMockSolver"
+}
+
+func TestSolver(t *testing.T) {
+	defer puzzles.UnregisterAllSolvers(t)
+
+	solvers := map[string]puzzles.Solver{
+		"mock":        mockSolver{},
+		"anotherMock": anotherMockSolver{},
+	}
+
+	solversList := make([]string, 0, len(solvers))
+
+	for name, solver := range solvers {
+		puzzles.Register(name, solver)
+		solversList = append(solversList, name)
+	}
+
+	// get existing solver
+	gotSolver, err := puzzles.GetSolver("mock")
+	assert.NoError(t, err)
+	assert.IsType(t, mockSolver{}, gotSolver)
+
+	// get existing solver
+	gotSolver, err = puzzles.GetSolver("anotherMock")
+	assert.NoError(t, err)
+	assert.IsType(t, anotherMockSolver{}, gotSolver)
+
+	// get not existing solver
+	gotSolver, err = puzzles.GetSolver("not-existed")
+	assert.Error(t, err)
+	assert.IsType(t, nil, gotSolver)
+
+	// get solvers list
+	gotList := puzzles.Solvers()
+	assert.ElementsMatch(t, solversList, gotList)
+
+	assert.Panics(t, func() {
+		puzzles.UnregisterAllSolvers(nil)
+	})
+}