feat(cache): make dummy cache error ignorable

All "dummy" cache methods throw by design.
This PR makes the corresponding errors ignorable so that the logs are less verbose and always use the DEBUG level.

Author: vicb

packages/open-next/src/adapters/cache.ts

@@ -1,3 +1,4 @@
+import { IgnorableError, isIgnorableError } from "utils/error";
 import { isBinaryContentType } from "./binary";
 import { debug, error, warn } from "./logger";
 
@@ -192,7 +193,11 @@ export default class S3Cache {
       } as CacheHandlerValue;
     } catch (e) {
       // We can usually ignore errors here as they are usually due to cache not being found
-      debug("Failed to get fetch cache", e);
+      if (isIgnorableError(e)) {
+        debug("Failed to get fetch cache", e.message);
+      } else {
+        debug("Failed to get fetch cache", e);
+      }
       return null;
     }
   }
@@ -271,7 +276,11 @@ export default class S3Cache {
       return null;
     } catch (e) {
       // We can usually ignore errors here as they are usually due to cache not being found
-      debug("Failed to get body cache", e);
+      if (isIgnorableError(e)) {
+        debug("Failed to get body cache", e.message);
+      } else {
+        debug("Failed to get body cache", e);
+      }
       return null;
     }
   }
@@ -409,7 +418,11 @@ export default class S3Cache {
       }
       debug("Finished setting cache");
     } catch (e) {
-      error("Failed to set cache", e);
+      if (isIgnorableError(e)) {
+        debug("Failed to set cache", e.message);
+      } else {
+        error("Failed to set cache", e);
+      }
     } finally {
       // We need to resolve the promise even if there was an error
       detachedPromise?.resolve();
@@ -456,7 +469,11 @@ export default class S3Cache {
         await globalThis.tagCache.writeTags(toInsert);
       }
     } catch (e) {
-      error("Failed to revalidate tag", e);
+      if (isIgnorableError(e)) {
+        debug("Failed to revalidate tag", e.message);
+      } else {
+        error("Failed to revalidate tag", e);
+      }
     }
   }
 }

packages/open-next/src/overrides/incrementalCache/dummy.ts

@@ -1,15 +1,16 @@
 import type { IncrementalCache } from "types/overrides";
+import { IgnorableError } from "utils/error";
 
 const dummyIncrementalCache: IncrementalCache = {
   name: "dummy",
   get: async () => {
-    throw new Error("Dummy cache is not implemented");
+    throw new IgnorableError('"Dummy" cache does not cache anything');
   },
   set: async () => {
-    throw new Error("Dummy cache is not implemented");
+    throw new IgnorableError('"Dummy" cache does not cache anything');
   },
   delete: async () => {
-    throw new Error("Dummy cache is not implemented");
+    throw new IgnorableError('"Dummy" cache does not cache anything');
   },
 };
 

packages/open-next/src/utils/error.ts

@@ -5,6 +5,8 @@ export interface BaseOpenNextError {
   readonly logLevel: 0 | 1 | 2;
 }
 
+const IGNORABLE_ERROR_NAME = "IgnorableError";
+
 // This is an error that can be totally ignored
 // It don't even need to be logged, or only in debug mode
 export class IgnorableError extends Error implements BaseOpenNextError {
@@ -13,10 +15,17 @@ export class IgnorableError extends Error implements BaseOpenNextError {
   readonly logLevel = 0;
   constructor(message: string) {
     super(message);
-    this.name = "IgnorableError";
+    this.name = IGNORABLE_ERROR_NAME;
   }
 }
 
+// Note that `e instanceof IgnorableError` might not work across bundles
+// embedding a distinct implementation of `IgnorableError`.
+export function isIgnorableError(error: unknown): error is IgnorableError {
+  const anyError = error as any;
+  return anyError.__openNextInternal && anyError.name === IGNORABLE_ERROR_NAME;
+}
+
 // This is an error that can be recovered from
 // It should be logged but the process can continue
 export class RecoverableError extends Error implements BaseOpenNextError {