fix: handle pre-release versions in compareVersions

src/cli/commands/update/__tests__/update-action.test.ts

@@ -50,6 +50,30 @@ describe('compareVersions', () => {
   it('handles versions with missing parts', () => {
     expect(compareVersions('1.0', '1.0.0')).toBe(0);
   });
+
+  it('returns 1 when latest pre-release is newer', () => {
+    expect(compareVersions('0.3.0-preview.1.0', '0.3.0-preview.2.0')).toBe(1);
+  });
+
+  it('returns -1 when current pre-release is newer', () => {
+    expect(compareVersions('0.3.0-preview.2.0', '0.3.0-preview.1.0')).toBe(-1);
+  });
+
+  it('returns 0 for equal pre-release versions', () => {
+    expect(compareVersions('0.3.0-preview.1.0', '0.3.0-preview.1.0')).toBe(0);
+  });
+
+  it('returns 1 when latest is release and current is pre-release', () => {
+    expect(compareVersions('1.0.0-preview.1', '1.0.0')).toBe(1);
+  });
+
+  it('returns -1 when current is release and latest is pre-release', () => {
+    expect(compareVersions('1.0.0', '1.0.0-preview.1')).toBe(-1);
+  });
+
+  it('compares pre-release labels lexicographically', () => {
+    expect(compareVersions('1.0.0-alpha.1', '1.0.0-beta.1')).toBe(1);
+  });
 });
 
 describe('fetchLatestVersion', () => {

src/cli/commands/update/action.ts

@@ -14,15 +14,52 @@ export async function fetchLatestVersion(): Promise<string> {
 }
 
 export function compareVersions(current: string, latest: string): number {
-  const currentParts = current.split('.').map(Number);
-  const latestParts = latest.split('.').map(Number);
+  const parse = (v: string) => {
+    const [core = '', ...prereleaseParts] = v.split('-');
+    const nums = core.split('.').map(Number);
+    const prerelease = prereleaseParts.join('-');
+    return { nums, prerelease };
+  };
 
+  const curr = parse(current);
+  const lat = parse(latest);
+
+  // Compare major.minor.patch
   for (let i = 0; i < 3; i++) {
-    const curr = currentParts[i] ?? 0;
-    const lat = latestParts[i] ?? 0;
-    if (lat > curr) return 1;
-    if (lat < curr) return -1;
+    const c = curr.nums[i] ?? 0;
+    const l = lat.nums[i] ?? 0;
+    if (l > c) return 1;
+    if (l < c) return -1;
+  }
+
+  // Equal core versions — compare pre-release segments
+  if (!curr.prerelease && !lat.prerelease) return 0;
+  // A version without pre-release is greater than one with (1.0.0 > 1.0.0-preview)
+  if (!curr.prerelease) return -1;
+  if (!lat.prerelease) return 1;
+
+  const currSegments = curr.prerelease.split('.');
+  const latSegments = lat.prerelease.split('.');
+  const len = Math.max(currSegments.length, latSegments.length);
+
+  for (let i = 0; i < len; i++) {
+    const cs = currSegments[i];
+    const ls = latSegments[i];
+    if (cs === undefined) return 1; // fewer segments = earlier
+    if (ls === undefined) return -1;
+    const cn = Number(cs);
+    const ln = Number(ls);
+    // Both numeric — compare numerically
+    if (!isNaN(cn) && !isNaN(ln)) {
+      if (ln > cn) return 1;
+      if (ln < cn) return -1;
+    } else {
+      // Lexicographic comparison for non-numeric segments
+      if (ls > cs) return 1;
+      if (ls < cs) return -1;
+    }
   }
+
   return 0;
 }