fix(cache): distinguish between null and undefined (#6509)

null = this lookup returned nothing last time
undefined = no cached result found

lib/datasource/cache.ts

@@ -60,7 +60,7 @@ export async function cacheAble<TArg, TResult = unknown>({
   const cacheKey = JSON.stringify(lookup);
   const cachedResult = await globalCache.get<TResult>(cacheNamespace, cacheKey);
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     logger.trace({ id, lookup }, 'datasource cachedResult');
     return cachedResult;
   }

lib/datasource/crate/index.ts

@@ -22,7 +22,7 @@ export async function getReleases({
     cacheKey
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
 

lib/datasource/docker/index.ts

@@ -341,7 +341,7 @@ export async function getDigest(
     const cacheKey = `${registry}:${repository}:${newTag}`;
     const cachedResult = await globalCache.get(cacheNamespace, cacheKey);
     // istanbul ignore if
-    if (cachedResult) {
+    if (cachedResult !== undefined) {
       return cachedResult;
     }
     const manifestResponse = await getManifestResponse(
@@ -386,7 +386,7 @@ async function getTags(
       cacheKey
     );
     // istanbul ignore if
-    if (cachedResult) {
+    if (cachedResult !== undefined) {
       return cachedResult;
     }
     // AWS ECR limits the maximum number of results to 1000
@@ -486,7 +486,7 @@ async function getLabels(
     cacheKey
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   try {

lib/datasource/galaxy/index.ts

@@ -22,7 +22,7 @@ export async function getReleases({
     cacheKey
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
 

lib/datasource/git-refs/index.ts

@@ -29,7 +29,7 @@ export async function getRawRefs({
       lookupName
     );
     /* istanbul ignore next line */
-    if (cachedResult) {
+    if (cachedResult !== undefined) {
       return cachedResult;
     }
 

lib/datasource/git-submodules/index.ts

@@ -18,7 +18,7 @@ export async function getReleases({
     cacheKey
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
 

lib/datasource/github-releases/index.ts

@@ -33,7 +33,7 @@ export async function getReleases({
     repo
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   try {

lib/datasource/github-tags/index.ts

@@ -29,7 +29,7 @@ async function getTagCommit(
     getCacheKey(githubRepo, `tag-${tag}`)
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   let digest: string;
@@ -81,7 +81,7 @@ export async function getDigest(
     getCacheKey(githubRepo, 'commit')
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   let digest: string;
@@ -95,9 +95,6 @@ export async function getDigest(
       'Error getting latest commit from GitHub repo'
     );
   }
-  if (!digest) {
-    return null;
-  }
   const cacheMinutes = 10;
   await globalCache.set(
     cacheNamespace,
@@ -105,7 +102,7 @@ export async function getDigest(
     digest,
     cacheMinutes
   );
-  return digest;
+  return digest || null;
 }
 
 /**
@@ -127,7 +124,7 @@ export async function getReleases({
     getCacheKey(repo, 'tags')
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   try {

lib/datasource/gitlab-tags/index.ts

@@ -35,7 +35,7 @@ export async function getReleases({
     getCacheKey(depHost, repo)
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
 

lib/datasource/helm/index.ts

@@ -21,7 +21,7 @@ export async function getRepositoryData(
   const cacheKey = repository;
   const cachedIndex = await globalCache.get(cacheNamespace, cacheKey);
   // istanbul ignore if
-  if (cachedIndex) {
+  if (cachedIndex !== undefined) {
     return cachedIndex;
   }
   let res: any;

lib/datasource/maven/index.ts

@@ -162,7 +162,7 @@ async function getVersionsFromMetadata(
     cacheKey
   );
   /* istanbul ignore if */
-  if (cachedVersions) {
+  if (cachedVersions !== undefined) {
     return cachedVersions;
   }
 

lib/datasource/npm/get.ts

@@ -75,7 +75,7 @@ export async function getDependency(
     pkgUrl
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   const headers: OutgoingHttpHeaders = {};

lib/datasource/nuget/v3.ts

@@ -24,7 +24,7 @@ export async function getQueryUrl(url: string): Promise<string | null> {
   const cachedResult = await globalCache.get<string>(cacheNamespace, cacheKey);
 
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
 

lib/datasource/orb/index.ts

@@ -31,7 +31,7 @@ export async function getReleases({
     cacheKey
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   const url = 'https://circleci.com/graphql-unstable';

lib/datasource/packagist/index.ts

@@ -236,7 +236,7 @@ async function packagistOrgLookup(name: string): Promise<ReleaseResult> {
     name
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   let dep: ReleaseResult = null;

lib/datasource/pod/index.ts

@@ -158,7 +158,7 @@ export async function getReleases({
     podName
   );
   /* istanbul ignore next line */
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     logger.debug(`CocoaPods: Return cached result for ${podName}`);
     return cachedResult;
   }

lib/datasource/repology/index.ts

@@ -89,7 +89,7 @@ async function getCachedPackage(
     cacheKey
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
 

lib/datasource/ruby-version/index.ts

@@ -21,7 +21,7 @@ export async function getReleases(
     'all'
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   try {

lib/datasource/terraform-module/index.ts

@@ -71,7 +71,7 @@ export async function getReleases({
     pkgUrl
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   try {

lib/datasource/terraform-provider/index.ts

@@ -34,7 +34,7 @@ export async function getReleases({
     pkgUrl
   );
   // istanbul ignore if
-  if (cachedResult) {
+  if (cachedResult !== undefined) {
     return cachedResult;
   }
   try {