fix(gomod): treat v0 pseudo version updates as digest updates

lib/workers/repository/process/lookup/generate.ts

@@ -11,6 +11,7 @@ import { getUpdateType } from './update-type';
 export async function generateUpdate(
   config: LookupUpdateConfig,
   currentValue: string | undefined,
+  currentDigest: string | undefined,
   versioning: VersioningApi,
   rangeStrategy: RangeStrategy,
   currentVersion: string,
@@ -68,8 +69,30 @@ export async function generateUpdate(
   } else {
     update.newValue = currentValue;
   }
-  update.newMajor = versioning.getMajor(newVersion)!;
-  update.newMinor = versioning.getMinor(newVersion)!;
+
+  const newMajor = versioning.getMajor(newVersion);
+  if (is.number(newMajor)) {
+    update.newMajor = newMajor;
+  }
+
+  const newMinor = versioning.getMinor(newVersion);
+  if (is.number(newMinor)) {
+    update.newMinor = newMinor;
+  }
+
+  const newPatch = versioning.getPatch(newVersion);
+
+  // istanbul ignore next
+  if (
+    update.newDigest &&
+    currentDigest !== update.newDigest &&
+    newMajor === versioning.getMajor(currentVersion) &&
+    newMinor === versioning.getMinor(currentVersion) &&
+    newPatch === versioning.getPatch(currentVersion)
+  ) {
+    update.updateType = 'digest';
+  }
+
   // istanbul ignore if
   if (!update.updateType && !currentVersion) {
     logger.debug({ update }, 'Update has no currentVersion');

lib/workers/repository/process/lookup/index.spec.ts

@@ -3492,7 +3492,6 @@ describe('workers/repository/process/lookup/index', () => {
           {
             bucket: 'major',
             newMajor: 9,
-            newMinor: null,
             newValue: '9',
             newVersion: '9',
             updateType: 'major',
@@ -3664,7 +3663,6 @@ describe('workers/repository/process/lookup/index', () => {
           {
             bucket: 'major',
             newMajor: 12,
-            newMinor: null,
             newValue: 'bookworm-slim',
             newVersion: 'bookworm',
             updateType: 'major',

lib/workers/repository/process/lookup/index.ts

@@ -401,6 +401,7 @@ export async function lookupUpdates(
         const update = await generateUpdate(
           config,
           compareValue,
+          config.currentDigest,
           versioning,
           // TODO #22198