Add CouchDB cache compatibility controls and native revalidation

src/common/replicatorConfigurationIdentity.ts

@@ -82,6 +82,7 @@ export function getCouchDBReplicatorConfigurationIdentity(settings: RemoteDBSett
         authentication,
         projectHeaders(settings.couchDB_CustomHeaders),
         settings.useRequestAPI,
+        settings.useCouchDBCacheControlHeadersOnly === true,
         settings.disableRequestURI,
         projectRemoteSecurity(settings),
         usesEncryptedInternalMetadata(settings),

src/common/replicatorConfigurationIdentity.unit.spec.ts

@@ -7,6 +7,17 @@ import {
 } from "./replicatorConfigurationIdentity";
 
 describe("active Replicator configuration identity", () => {
+    it("treats an absent headers-only CouchDB cache switch as off and leaves Object Storage unaffected", () => {
+        const absent = configuredSettings();
+        Reflect.deleteProperty(absent, "useCouchDBCacheControlHeadersOnly");
+        expect(getCouchDBReplicatorConfigurationIdentity({ ...absent, useCouchDBCacheControlHeadersOnly: false })).toBe(
+            getCouchDBReplicatorConfigurationIdentity(absent)
+        );
+        expect(getObjectStorageReplicatorConfigurationIdentity({ ...absent, useCouchDBCacheControlHeadersOnly: true })).toBe(
+            getObjectStorageReplicatorConfigurationIdentity(absent)
+        );
+    });
+
     it("replaces a connection when the path identity mode changes", () => {
         const previous = configuredSettings({ pathNormalizationVersion: 0 });
         const next = { ...previous, pathNormalizationVersion: 1 as const };
@@ -73,6 +84,7 @@ describe("active Replicator configuration identity", () => {
         ["couchDB_PASSWORD", "secret-b"],
         ["couchDB_CustomHeaders", "X-First: changed"],
         ["useRequestAPI", true],
+        ["useCouchDBCacheControlHeadersOnly", true],
         ["disableRequestURI", true],
         ["encrypt", false],
         ["passphrase", "encryption-b"],

src/modules/features/SettingDialogue/PanePowerUsers.ts

@@ -28,6 +28,7 @@ export function panePowerUsers(
             onUpdate: this.onlyOnCouchDB,
         });
         new Setting(paneEl).autoWireToggle("useTimeouts", { onUpdate: this.onlyOnCouchDB });
+        new Setting(paneEl).autoWireToggle("useCouchDBCacheControlHeadersOnly", { onUpdate: this.onlyOnCouchDB });
     });
     void addPanel(paneEl, $msg("Configuration Encryption")).then((paneEl) => {
         const passphrase_options: Record<ConfigPassphraseStore, string> = {

src/modules/services/ObsidianAPIService.ts

@@ -220,8 +220,9 @@ export class ObsidianAPIService extends InjectableAPIService<ObsidianServiceCont
         delete transformedHeaders["content-length"];
         delete transformedHeaders["Content-Length"];
         const cacheMode = opts?.cache ?? (req instanceof Request ? req.cache : undefined);
-        if (cacheMode === "no-store" && ["GET", "HEAD"].includes(method.toUpperCase())) {
+        if (["no-cache", "no-store"].includes(cacheMode ?? "") && ["GET", "HEAD"].includes(method.toUpperCase())) {
             // requestUrl has no cache option; no-store alone can reuse an existing cached response.
+            const enforceNoStore = cacheMode === "no-store";
             const cacheControlKeys = Object.keys(transformedHeaders).filter(
                 (key) => key.toLowerCase() === "cache-control"
             );
@@ -229,11 +230,19 @@ export class ObsidianAPIService extends InjectableAPIService<ObsidianServiceCont
                 .flatMap((key) => splitHeaderDirectives(transformedHeaders[key]))
                 .filter((directive) => {
                     const name = getDirectiveName(directive);
-                    return !cacheReuseDirectives.has(name) && name !== "no-cache" && name !== "no-store";
+                    return (
+                        !cacheReuseDirectives.has(name) &&
+                        name !== "no-cache" &&
+                        (!enforceNoStore || name !== "no-store")
+                    );
                 });
             const cacheControlKey = cacheControlKeys[0] ?? "cache-control";
             for (const key of cacheControlKeys) delete transformedHeaders[key];
-            transformedHeaders[cacheControlKey] = [...cacheControlDirectives, "no-cache", "no-store"].join(", ");
+            transformedHeaders[cacheControlKey] = [
+                ...cacheControlDirectives,
+                "no-cache",
+                ...(enforceNoStore ? ["no-store"] : []),
+            ].join(", ");
 
             const pragmaKeys = Object.keys(transformedHeaders).filter((key) => key.toLowerCase() === "pragma");
             const pragmaDirectives = pragmaKeys

src/modules/services/ObsidianAPIService.unit.spec.ts

@@ -101,6 +101,35 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(mocks.requestUrl.mock.calls[0][0]).toMatchObject({ url, method });
     });
 
+    it.each(["GET", "HEAD", "get", "head"])("revalidates an explicit no-cache %s request", async (method) => {
+        const headers = {
+            "Cache-Control": 'public, max-age=3600, no-transform, custom="a,b"',
+            "cAcHe-CoNtRoL": 'max-stale=30, min-fresh=5, only-if-cached, custom-two="max-age=1, only-if-cached"',
+            Pragma: "cache",
+        };
+        const originalHeaders = { ...headers };
+
+        await createService({}).nativeFetch(url, { method, cache: "no-cache", headers });
+
+        expect(sentHeaders().get("cache-control")).toBe(
+            'public, no-transform, custom="a,b", custom-two="max-age=1, only-if-cached", no-cache'
+        );
+        expect(sentHeaders().get("pragma")).toBe("cache, no-cache");
+        expect(headers).toEqual(originalHeaders);
+        expect(mocks.requestUrl.mock.calls[0][0]).toMatchObject({ url, method });
+    });
+
+    it("preserves an explicit no-store directive when enforcing no-cache", async () => {
+        const headers = { "Cache-Control": "no-store, max-age=3600", Pragma: "legacy" };
+        const originalHeaders = { ...headers };
+
+        await createService({}).nativeFetch(url, { cache: "no-cache", headers });
+
+        expect(sentHeaders().get("cache-control")).toBe("no-store, no-cache");
+        expect(sentHeaders().get("pragma")).toBe("legacy, no-cache");
+        expect(headers).toEqual(originalHeaders);
+    });
+
     it("preserves non-conflicting cache directives when enforcing no-store", async () => {
         const headers = {
             "Cache-Control": 'max-age=3600, no-transform, custom="a,b"',
@@ -140,6 +169,30 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(request.headers.has("cache-control")).toBe(false);
     });
 
+    it("uses a Request no-cache mode when the options do not override it", async () => {
+        const request = new Request(url, {
+            method: "HEAD",
+            cache: "no-cache",
+            headers: { "Cache-Control": "max-age=60", "X-Fixture": "request" },
+        });
+        const headers = new Headers({ "X-Other": "options" });
+
+        await createService({}).nativeFetch(request, { headers });
+
+        expect(sentHeaders().get("cache-control")).toBe("no-cache");
+        expect(sentHeaders().get("x-fixture")).toBe("request");
+        expect(sentHeaders().get("x-other")).toBe("options");
+        expect(request.headers.get("cache-control")).toBe("max-age=60");
+        expect(headers.has("cache-control")).toBe(false);
+    });
+
+    it("lets an explicit default cache mode override a no-cache Request", async () => {
+        await createService({}).nativeFetch(new Request(url, { cache: "no-cache" }), { cache: "default" });
+
+        expect(sentHeaders().has("cache-control")).toBe(false);
+        expect(sentHeaders().has("pragma")).toBe(false);
+    });
+
     it("lets the options request no-store for an otherwise cacheable Request", async () => {
         await createService({}).nativeFetch(new Request(url, { cache: "force-cache" }), { cache: "no-store" });
 
@@ -153,7 +206,7 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(sentHeaders().has("pragma")).toBe(false);
     });
 
-    it.each([undefined, "default", "no-cache", "reload", "force-cache"] as const)(
+    it.each([undefined, "default", "reload", "force-cache"] as const)(
         "preserves caller headers for cache mode %s",
         async (cache) => {
             const headers = { "Cache-Control": "max-age=60", Pragma: "fixture" };
@@ -171,6 +224,14 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(sentHeaders().has("pragma")).toBe(false);
     });
 
+    it.each(["POST", "PUT", "DELETE"])("preserves a no-cache %s request", async (method) => {
+        const headers = { "Cache-Control": "max-age=60, no-transform", Pragma: "fixture" };
+
+        await createService({}).nativeFetch(url, { method, cache: "no-cache", headers });
+
+        expect(mocks.requestUrl.mock.calls[0][0]).toMatchObject({ url, method, headers });
+    });
+
     it.each(["POST", "PUT", "DELETE"])("preserves a no-store %s request", async (method) => {
         const headers = { "Cache-Control": "no-transform" };