quak login --server: log in to a self-hosted Ente server (closes #243)

`quak login` takes the server's API address from `--server` or
`QUAK_SERVER`. `isServerAddress` refuses anything but an http or https
URL with no query or fragment, there and in `Client.fromJSON`. The
client's snapshot keeps a non-default `apiOrigin`, so the session file
names the server and every later command uses it.

Two servers can give two accounts, and two files, the same ID. A
self-hosted account's default cache directory therefore names the
server, and `metadata.json` records it: `Library.open` deletes a cache
from another server whole. `originalOf` and `thumbnailOf` record the
account in a cache that names none before storing a file, and `open`
treats a cache with no collection as empty. This fixes
#254 (closes #254).

Model: opus-5-5

test/cli/commands.test.ts

@@ -445,6 +445,21 @@ describe("login", () => {
             );
         },
     );
+
+    it("refuses an empty QUAK_SERVER before asking for anything", async () => {
+        vi.stubEnv("QUAK_SERVER", "");
+        const ctx = loginContext(async () => {
+            throw new Error("login must not be called");
+        });
+        expect(await loginCommand(ctx, {})).toBe(1);
+
+        expect(prompts).toEqual([]);
+        expect(stderr.text).toBe(
+            `Invalid server address "": it must be an http or https URL ` +
+                `with no query or fragment\n`,
+        );
+        expect(existsSync(join(ctx.sessionDir, "session.json"))).toBe(false);
+    });
 });
 
 // These use a real client read from the session file, over a fake API that

test/client/session.test.ts

@@ -55,10 +55,25 @@ describe("Client.toJSON", () => {
         expect(Client.fromJSON(snapshot).toJSON()).toEqual(snapshot);
     });
 
-    it("names the server apiOptions gave fromJSON", () => {
+    it("names the server apiOptions gave fromJSON", async () => {
         const apiOrigin = "https://ente.example.com";
-        const client = Client.fromJSON(validSnapshot(), { apiOrigin });
+        const urls: string[] = [];
+        const client = Client.fromJSON(validSnapshot(), {
+            apiOrigin,
+            fetch: async (input) => {
+                urls.push(String(input));
+                return new Response(JSON.stringify({ collections: [] }), {
+                    status: 200,
+                    headers: { "content-type": "application/json" },
+                });
+            },
+        });
         expect(client.toJSON().apiOrigin).toBe(apiOrigin);
+
+        await client.listCollections();
+        expect(urls).toEqual([
+            "https://ente.example.com/collections/v2?sinceTime=0",
+        ]);
     });
 
     it("throws instead of emitting a snapshot without a token", () => {

test/library/library.test.ts

@@ -33,7 +33,8 @@
  * 10. A cache another account filled starts empty. One filled from another
  *     server also loses its originals and thumbnails, since two servers can
  *     give two files the same ID. `thumbnailOf` on an empty cache saves the
- *     account's user ID and server.
+ *     account's user ID and server. A refresh saves the account's server, so a
+ *     self-hosted account keeps its own cache from one `open()` to the next.
  *
  * The client is a mock: no crypto, no network. It serves scripted pages and
  * records the `sinceTime` each call carried so cursor threading is provable.
@@ -1016,4 +1017,41 @@ describe("Library.open and background refresh", () => {
         expect(saved.userID).toBe(USER_ID);
         expect(saved.apiOrigin).toBe("https://ente.example.com");
     });
+
+    // A refresh saves the account's server in `metadata.json`. Without it,
+    // `open()` would take a self-hosted account's own cache for another
+    // server's and delete it.
+    it("keeps a self-hosted account's own cache from one open to the next", async () => {
+        const client = new MockClient();
+        client.apiOrigin = "https://ente.example.com";
+        client.collectionsQueue.push({
+            collections: [collection(1, 100)],
+            deleted: [],
+            cursor: 100,
+        });
+        const first = await Library.open({
+            client,
+            cacheDirectory,
+            refreshIntervalSeconds: Infinity,
+        });
+        await first.close();
+        mkdirSync(join(cacheDirectory, "originals"));
+        writeFileSync(join(cacheDirectory, "originals", "1001.jpg"), "1001");
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshIntervalSeconds: Infinity,
+        });
+        try {
+            expect(lib.listCollections().map((c) => c.id)).toEqual([1]);
+            expect(
+                existsSync(join(cacheDirectory, "originals", "1001.jpg")),
+            ).toBe(true);
+        } finally {
+            await lib.close();
+        }
+        // The second open's refresh started from the saved cursor.
+        expect(client.collectionsSinceTimes).toEqual([0, 100]);
+    });
 });