fix(bump): auto-increment unnamed prerelease when tag already exists

Author: SLASHLogin

lib/lifecycles/bump.js

@@ -290,9 +290,17 @@ async function resolveUniquePrereleaseVersion(
     const base = `${parsed.major}.${parsed.minor}.${parsed.patch}`;
     const build = parsed.build; // preserve build metadata if present
 
-    // Current numeric index if present, otherwise default to 0
-    const currentNum =
-      typeof parsed.prerelease[1] === 'number' ? parsed.prerelease[1] : 0;
+    // Determine current numeric index depending on named vs unnamed prerelease
+    let currentNum = 0;
+    if (Array.isArray(parsed.prerelease) && parsed.prerelease.length) {
+      if (prereleaseId === '' && typeof parsed.prerelease[0] === 'number') {
+        // unnamed prerelease like 1.2.3-0
+        currentNum = parsed.prerelease[0];
+      } else if (typeof parsed.prerelease[1] === 'number') {
+        // named prerelease like 1.2.3-alpha.0
+        currentNum = parsed.prerelease[1];
+      }
+    }
 
     const tags = await new Promise((resolve, reject) => {
       gitSemverTags({ tagPrefix }, (err, t) =>
@@ -306,22 +314,29 @@ async function resolveUniquePrereleaseVersion(
       .map((t) => (semver.valid(t) ? semver.clean(t) : null))
       .filter(Boolean);
 
-    // collect numeric suffix for same base and prerelease id
+    // collect numeric suffix for same base and prerelease id (or unnamed prerelease)
     const nums = cleaned
       .filter((t) => {
         const v = new semver.SemVer(t);
         if (!Array.isArray(v.prerelease) || v.prerelease.length === 0)
           return false;
-        // same base version and same prerelease id
-        return (
+        const sameBase =
           v.major === parsed.major &&
           v.minor === parsed.minor &&
-          v.patch === parsed.patch &&
-          String(v.prerelease[0]) === String(prereleaseId)
-        );
+          v.patch === parsed.patch;
+        if (!sameBase) return false;
+        if (prereleaseId === '') {
+          // unnamed prerelease: include tags where first prerelease token is numeric
+          return typeof v.prerelease[0] === 'number';
+        }
+        // named prerelease: match by identifier
+        return String(v.prerelease[0]) === String(prereleaseId);
       })
       .map((t) => {
         const v = new semver.SemVer(t);
+        if (prereleaseId === '') {
+          return typeof v.prerelease[0] === 'number' ? v.prerelease[0] : 0;
+        }
         return typeof v.prerelease[1] === 'number' ? v.prerelease[1] : 0;
       });
 
@@ -333,7 +348,10 @@ async function resolveUniquePrereleaseVersion(
     const maxExisting = Math.max(...nums);
     // If our proposed numeric index is already used or below max, bump to max + 1
     if (currentNum <= maxExisting) {
-      let candidate = `${base}-${prereleaseId}.${maxExisting + 1}`;
+      let candidate =
+        prereleaseId === ''
+          ? `${base}-${maxExisting + 1}`
+          : `${base}-${prereleaseId}.${maxExisting + 1}`;
       // re-append build metadata if any
       if (build && build.length) {
         candidate = semvarToVersionStr(candidate, build);

test/git.integration-test.js

@@ -248,6 +248,27 @@ describe('git', function () {
     expect(getPackageVersion()).toEqual('1.1.0-0');
   });
 
+  it('increments unnamed prerelease number when unnamed prerelease tag already exists', async function () {
+    writePackageJson('1.2.3');
+    // Existing unnamed prerelease tag 1.2.3-0 exists
+    mock({ bump: 'patch', tags: ['v1.2.3-0'] });
+    await exec('--prerelease');
+    expect(getPackageVersion()).toEqual('1.2.4-0');
+    // Now start from a prerelease of same base to trigger unnamed collision
+    writePackageJson('1.2.3-0');
+    mock({ bump: 'patch', tags: ['v1.2.3-0'] });
+    await exec('--prerelease');
+    expect(getPackageVersion()).toEqual('1.2.3-1');
+  });
+
+  it('increments unnamed prerelease number with gitTagFallback when unnamed prerelease tag already exists', async function () {
+    shell.rm('package.json');
+    mock({ bump: 'patch', tags: ['v1.2.3-0'] });
+    await exec({ packageFiles: [], gitTagFallback: true, prerelease: '' });
+    const output = shell.exec('git tag').stdout;
+    expect(output).toMatch(/v1\.2\.3-1/);
+  });
+
   it('increments prerelease number when same prerelease tag already exists', async function () {
     writePackageJson('1.4.3-abc.0');
     // Simulate existing tags where v1.4.3-xyz.0 already exists from git history