fix tests

commands.go

@@ -527,6 +527,10 @@ func (b *bot) ban(m dggchat.Message, s *dggchat.Session) {
 	}
 }
 
+var errInputFormat = errors.New("invalid input format")
+var errInputBounds = errors.New("input out of bounds")
+var errResultRangeBounds = errors.New("result range out of bounds")
+
 func computeRoll(input string) (int, error) {
 
 	// Define a regular expression to extract dice rolling information
@@ -537,7 +541,7 @@ func computeRoll(input string) (int, error) {
 	matches := regex.FindStringSubmatch(input)
 
 	if matches == nil {
-		return 0, fmt.Errorf("invalid input format: %s", input)
+		return 0, fmt.Errorf("%w: %s", errInputFormat, input)
 	}
 
 	// Extract matched values
@@ -553,13 +557,13 @@ func computeRoll(input string) (int, error) {
 	checkMod := modifier != 0
 
 	if numSides <= 0 || numDice <= 0 || numDice > 1000 {
-		return 0, errors.New("sides, count or modifier too large")
+		return 0, errInputBounds
 	}
 
 	if math.MaxInt64/numSides < numDice ||
 		(modifier > 0 && math.MaxInt64-numSides*numDice < modifier) ||
 		(modifier < 0 && math.MinInt64+numSides*numDice > modifier) {
-		return 0, errors.New("sides, count or modifier too large")
+		return 0, errResultRangeBounds
 	}
 
 	// Roll the dice

commands_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 )
@@ -23,29 +24,32 @@ func TestParseModifiers(t *testing.T) {
 }
 
 func TestComputeRoll(t *testing.T) {
-	testInputs := []string{
-		"!roll 2d2+100 foo biz baz",
-		"!roll 2d2 + 100",
-		"!roll 2d2 +100",
-		"!roll 2d2+ 100",
-		"!roll 2d2-100",
-		"!roll 2d2 - 100",
-		"!roll 2d2 -100",
-		"!roll 2d2- 100",
-		"!roll 2d2- 100 foo biz baz",
-		"!roll 23904823904823904823490d20 +1",
-		"!roll 2d20",
-		"!roll 20",
-		"!roll 20+10"}
+	testInputs := []struct {
+		input string
+		err   error
+	}{
+		{input: "!roll 2d2+100 foo biz baz"},
+		{input: "!roll 2d2 + 100"},
+		{input: "!roll 2d2 +100"},
+		{input: "!roll 2d2+ 100"},
+		{input: "!roll 2d2-100"},
+		{input: "!roll 2d2 - 100"},
+		{input: "!roll 2d2 -100"},
+		{input: "!roll 2d2- 100"},
+		{input: "!roll 2d2- 100 foo biz baz"},
+		{input: "!roll 2d20"},
+		{input: "!roll 20"},
+		{input: "!roll 20+10"},
+		{input: "!roll 1d9223372036854775807"},
+		{input: "!roll 1d9223372036854775807+1", err: errResultRangeBounds},
+		{input: "!roll 9223372036854775807d1", err: errInputBounds},
+	}
 
-	for _, input := range testInputs {
-		result, err := computeRoll(input)
-		errorMessage := fmt.Sprintf("%v", err)
-		if err != nil {
-			if errorMessage != "Sides, count or modifier too large" {
-				t.Error(fmt.Sprintf("Error: %v\n %d", err, result))
-			}
+	for _, c := range testInputs {
+		_, err := computeRoll(c.input)
+		if !errors.Is(err, c.err) {
+			fmt.Printf(`"%s": unexpected error %s\n`, c.input, err)
+			t.FailNow()
 		}
 	}
-
 }