Fix bug in trailing zero removal when version is all zeros

Changes.md

@@ -1,3 +1,7 @@
+## v0.0.6 2021-05-11
+
+* Fix bug in remove trailing zeros change when the version is all zeros.
+
 ## v0.0.5 2021-05-10
 
 * Remove trailing zeros from parsed package versions because version comparison

README.md

@@ -68,6 +68,16 @@ for details on this tool.
 
 [![CircleCI](https://circleci.com/gh/ActiveState/langtools.svg?style=svg)](https://circleci.com/gh/ActiveState/langtools)
 
+## To Create a New Release
+* Tag master: `git tag v0.0.6`
+* Push the tag: `git push origin v0.0.6`
+* Go to the [releases page](https://github.com/ActiveState/langtools/releases)
+* Click on the name of the new release, `v0.0.6` in this example
+* Click the `Edit Release` button on the top right
+* Enter in the release notes, which are the same as you added to `Changes.md`
+  * Remove any manual line breaks as they don't look good
+* Click the `Publish Release` button on the bottom
+
 ## Authors
 
 This library was created by:

pkg/version/shared_test.go

@@ -1,6 +1,7 @@
 package version
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/ericlagergren/decimal"
@@ -14,6 +15,7 @@ func TestParseGeneric(t *testing.T) {
 		version  string
 		expected []string
 	}{
+		{"Numbers", "0", []string{"0"}},
 		{"Numbers", "1", []string{"1"}},
 		{"Numbers", "1.0", []string{"1"}},
 		{"Numbers", "0.92", []string{"0", "92"}},
@@ -309,6 +311,32 @@ func TestString(t *testing.T) {
 	assert.Equal(t, "1.2.3 (SemVer)", v.String())
 }
 
+func TestTrimTrailingZeros(t *testing.T) {
+	tests := []struct {
+		input, expected []string
+	}{
+		{[]string{"0"}, []string{"0"}},
+		{[]string{"1"}, []string{"1"}},
+		{[]string{"0", "0"}, []string{"0"}},
+		{[]string{"0", "1"}, []string{"0", "1"}},
+		{[]string{"1", "0"}, []string{"1"}},
+		{[]string{"1", "1"}, []string{"1", "1"}},
+		{[]string{"0", "0", "0"}, []string{"0"}},
+		{[]string{"1", "0", "0"}, []string{"1"}},
+		{[]string{"1", "0", "1"}, []string{"1", "0", "1"}},
+		{[]string{"1", "1", "1"}, []string{"1", "1", "1"}},
+	}
+
+	for _, tt := range tests {
+		t.Run(fmt.Sprint(tt.input), func(t *testing.T) {
+			input := mustStringsToDecimal(t, tt.input)
+			actual := trimTrailingZeros(input)
+			expected := mustStringsToDecimal(t, tt.expected)
+			assert.Equal(t, expected, actual, "expected %v got %v", expected, actual)
+		})
+	}
+}
+
 func parseOrFatalGeneric(t *testing.T, v string) *Version {
 	ver, err := ParseGeneric(v)
 	assert.NoError(t, err, "no error parsing %s as a generic version", v)
@@ -322,3 +350,10 @@ func parseOrFatalSemVer(t *testing.T, v string) *Version {
 
 	return ver
 }
+
+func mustStringsToDecimal(t *testing.T, s []string) []*decimal.Big {
+	d, err := stringsToDecimals(s)
+	assert.NoError(t, err, "no error parsing strings to decimals")
+
+	return d
+}

pkg/version/version.go

@@ -111,9 +111,13 @@ func stringsToDecimals(strings []string) ([]*decimal.Big, error) {
 
 func trimTrailingZeros(decimals []*decimal.Big) []*decimal.Big {
 	indexOfLastZero := len(decimals)
-	for indexOfLastZero > 0 && decimals[indexOfLastZero-1].Cmp(bigZero) == 0 {
-		indexOfLastZero--
+	for i := len(decimals) - 1; i > 0; i-- {
+		if decimals[i].Cmp(bigZero) != 0 {
+			break
+		}
+		indexOfLastZero = i
 	}
+
 	return decimals[0:indexOfLastZero]
 }