feat(changelog): improve release detection

lib/workers/repository/update/pr/changelog/releases.spec.ts

@@ -122,5 +122,17 @@ describe('workers/repository/update/pr/changelog/releases', () => {
         { version: '1.2.0' },
       ]);
     });
+
+    it('should return any previous version if current version is non-existent', async () => {
+      const config = partial<BranchUpgradeConfig>({
+        datasource: 'some-datasource',
+        packageName: 'some-depname',
+        versioning: npmVersioning.id,
+        currentVersion: '1.0.2',
+        newVersion: '1.1.0',
+      });
+      const res = await releases.getInRangeReleases(config);
+      expect(res).toEqual([{ version: '1.0.1' }, { version: '1.1.0' }]);
+    });
   });
 });

lib/workers/repository/update/pr/changelog/releases.ts

@@ -41,22 +41,47 @@ export async function getInRangeReleases(
     const pkgReleases = (await getPkgReleases(config))!.releases;
     const version = get(versioning);
 
-    const releases = pkgReleases
+    const previousReleases = pkgReleases
       .filter((release) =>
         version.isCompatible(release.version, currentVersion)
       )
-      .filter(
-        (release) =>
-          version.equals(release.version, currentVersion) ||
-          version.isGreaterThan(release.version, currentVersion)
-      )
       .filter((release) => !version.isGreaterThan(release.version, newVersion))
       .filter(
         (release) =>
           version.isStable(release.version) ||
           matchesUnstable(version, currentVersion, release.version) ||
           matchesUnstable(version, newVersion, release.version)
       );
+
+    const releases = previousReleases.filter(
+      (release) =>
+        version.equals(release.version, currentVersion) ||
+        version.isGreaterThan(release.version, currentVersion)
+    );
+
+    /**
+     * If there is only one release, it can be one of two things:
+     *
+     *   1. There really is only one release
+     *
+     *   2. Pinned version doesn't actually exist, i.e pinning `^1.2.3` to `1.2.3`
+     *      while only `1.2.2` and `1.2.4` exist.
+     */
+    if (releases.length === 1) {
+      const newRelease = releases[0];
+      const closestPreviousRelease = previousReleases
+        .filter((release) => !version.equals(release.version, newVersion))
+        .sort((b, a) => version.sortVersions(a.version, b.version))
+        .shift();
+
+      if (
+        closestPreviousRelease &&
+        closestPreviousRelease.version !== newRelease.version
+      ) {
+        releases.unshift(closestPreviousRelease);
+      }
+    }
+
     if (version.valueToVersion) {
       for (const release of coerceArray(releases)) {
         release.version = version.valueToVersion(release.version);