fix(release): resolve stable alias version

Resolve Neovim's stable alias by extracting its concrete version and
matching that version against the release tag instead of comparing release
names. Add regression coverage for aliases whose names differ from the
concrete release.

Fixes: #19

Author: piraz

internal/release/info.go

@@ -124,10 +124,10 @@ func (rs *Releases) Process(data []byte, appOpts *config.AppOptions) error {
 	}
 
 	releases := (*rs)[:0]
-	var stable Info
+	stableVersion := ""
 	for _, info := range *rs {
 		if info.TagName == "stable" {
-			stable = info
+			stableVersion = extractStableVersion(info)
 			continue
 		}
 
@@ -148,10 +148,9 @@ func (rs *Releases) Process(data []byte, appOpts *config.AppOptions) error {
 		releases = append(releases, info)
 	}
 
-	for i, info := range releases {
-		if info.Name == stable.Name {
-			info.Stable = true
-			releases[i] = info
+	for i := range releases {
+		if releases[i].CleanTagName() == stableVersion {
+			releases[i].Stable = true
 		}
 	}
 	*rs = releases
@@ -233,7 +232,20 @@ func (i *Info) VersionLess(v string) bool {
 	return len(s1) < len(s2)
 }
 
-var checksumRe = regexp.MustCompile(`([a-f0-9]{64})\s+([^\s]+)`)
+var (
+	stableVersionRe = regexp.MustCompile(`(?i)\bv?(\d+\.\d+\.\d+)\b`)
+	checksumRe      = regexp.MustCompile(`([a-f0-9]{64})\s+([^\s]+)`)
+)
+
+func extractStableVersion(info Info) string {
+	for _, text := range []string{info.Body, info.Name} {
+		match := stableVersionRe.FindStringSubmatch(text)
+		if len(match) == 2 {
+			return match[1]
+		}
+	}
+	return ""
+}
 
 func (i *Info) ChecksumsFromBody() map[string]string {
 	result := make(map[string]string)

internal/release/info_test.go

@@ -0,0 +1,56 @@
+package release
+
+import (
+	"testing"
+
+	"github.com/candango/nvimim/internal/config"
+	"github.com/stretchr/testify/require"
+)
+
+func TestProcessResolvesStableAliasByConcreteVersion(t *testing.T) {
+	data := []byte(`[
+		{
+			"tag_name": "stable",
+			"name": "Nvim stable",
+			"body": "This release points to NVIM v0.12.4."
+		},
+		{
+			"tag_name": "v0.12.4",
+			"name": "Nvim v0.12.4"
+		},
+		{
+			"tag_name": "v0.12.3",
+			"name": "Nvim v0.12.3"
+		}
+	]`)
+
+	releases := Releases{}
+	err := releases.Process(data, &config.AppOptions{MinRelease: "0.7.0"})
+	require.NoError(t, err)
+
+	stable, err := releases.Get("stable")
+	require.NoError(t, err)
+	require.Equal(t, "0.12.4", stable.CleanTagName())
+}
+
+func TestProcessResolvesStableAliasFromNameWhenBodyHasNoVersion(t *testing.T) {
+	data := []byte(`[
+		{
+			"tag_name": "stable",
+			"name": "Nvim v0.12.4",
+			"body": "Stable release"
+		},
+		{
+			"tag_name": "v0.12.4",
+			"name": "Nvim 0.12.4"
+		}
+	]`)
+
+	releases := Releases{}
+	err := releases.Process(data, &config.AppOptions{MinRelease: "0.7.0"})
+	require.NoError(t, err)
+
+	stable, err := releases.Get("stable")
+	require.NoError(t, err)
+	require.Equal(t, "0.12.4", stable.CleanTagName())
+}