internal: Fix linters

Author: obalunenko

internal/puzzle/solver.go

@@ -29,31 +29,31 @@ var (
 func Register(name string, solver Solver) {
 	solversMu.Lock()
 	defer solversMu.Unlock()
+
 	if solver == nil {
 		panic("puzzle: Register solver is nil")
 	}
+
 	if _, dup := solvers[name]; dup {
 		panic("puzzle: Register called twice for solver " + name)
 	}
-	solvers[name] = solver
-}
 
-func unregisterAllSolvers() {
-	solversMu.Lock()
-	defer solversMu.Unlock()
-	// For tests.
-	solvers = make(map[string]Solver)
+	solvers[name] = solver
 }
 
 // Solvers returns a sorted list of the names of the registered puzzle solvers.
 func Solvers() []string {
 	solversMu.RLock()
 	defer solversMu.RUnlock()
-	var list []string
+
+	list := make([]string, 0, len(solvers))
+
 	for name := range solvers {
 		list = append(list, name)
 	}
+
 	sort.Strings(list)
+
 	return list
 }
 

internal/solutions/day01/fuel.go

@@ -3,7 +3,6 @@ package day01
 import (
 	"bufio"
 	"io"
-	"log"
 	"strconv"
 
 	"github.com/pkg/errors"
@@ -81,24 +80,21 @@ func calc(input io.Reader, calcFn calcFunc) (string, error) {
 		}
 		lines++
 	}
-	log.Printf("lines: %d\n", lines)
 
 	close(in)
 
 	if err = scanner.Err(); err != nil {
 		return "", errors.Wrap(err, "scanner error")
 	}
-	var resNumCount int
+
 	for lines > 0 {
 		select {
 		case r := <-res:
 			sum += r
-			resNumCount++
 		case <-done:
 			lines--
 		}
 	}
-	log.Printf("res count: %d \n", resNumCount)
 
 	close(res)
 

internal/solutions/day01/fuel_test.go

@@ -93,7 +93,10 @@ func Test_calcPart1(t *testing.T) {
 			want:  33583,
 		},
 	}
+
 	for _, tt := range tests {
+		tt := tt
+
 		t.Run(tt.name, func(t *testing.T) {
 			in <- module{mass: tt.input}
 
@@ -149,6 +152,7 @@ func Test_calcPart2(t *testing.T) {
 			want:  50346,
 		},
 	}
+
 	for _, tt := range tests {
 		tt := tt