An album whose folder cannot be made no longer stops the backup (closes #197)

Each album's folder, links and JSON are written inside one try. A failure
prints `FAILED album <name>: <reason>`, lists the album's ID in the result's
new `failedAlbums`, and so in `--json`, and makes `quak backup` exit 1. The
other albums and `failures.json` are still written.

An album whose folder would have another album's JSON name, ignoring case
(`x.json` beside `x`), gets its ID added. A folder or link name over 255
bytes gets the ID and is cut short between two characters by
`shortenToBytes` in `src/filename.ts`; a folder name leaves room for
`.json`. A link's ID stays right before its extension, which is cut short
only once nothing is left before the ID, so no two names with IDs match.

Apart from its call to `uniqueNames`, the album loop is only indented into
the try.

Model: opus-5-5

README.md

@@ -801,11 +801,12 @@ become `IMG_0001 (12345).JPG` and `IMG_0001 (12346).JPG`. A collection whose
 directory would have the name of another collection's JSON, again ignoring case,
 gets its ID added as well: beside an album `x`, whose JSON is `x.json`, an album
 named `x.json` gets the directory `x.json (12)/`. A name too long for a file
-name, which most file systems limit to 255 bytes, is cut short between two
-characters, just far enough that it fits with its ID added, and gets its ID; a
-collection's directory name also leaves room for the `.json` its JSON adds. IDs
-never change, so a name stays the same from run to run until such a clash
-appears or goes away.
+name, which most file systems limit to 255 bytes, gets its ID added too. A name
+with its ID added is cut short between two characters, just far enough that it
+fits: first the part before the ID, and once nothing is left of that, a
+symlink's extension. A collection's directory name also leaves room for the
+`.json` its JSON adds. IDs never change, so a name stays the same from run to
+run until such a clash appears or goes away.
 
 A collection whose directory or JSON cannot be written, such as one whose
 directory name is taken by a file you put in `collections/`, does not stop the

TODO.md

@@ -17,9 +17,11 @@ pre-1.0
 
 # Next Step
 
-Three bugs are open: https://git.eeqj.de/sneak/quak/issues/196,
-https://git.eeqj.de/sneak/quak/issues/198 and
-https://git.eeqj.de/sneak/quak/issues/199. The check of quak against a live Ente
+Five bugs are open: https://git.eeqj.de/sneak/quak/issues/196,
+https://git.eeqj.de/sneak/quak/issues/198,
+https://git.eeqj.de/sneak/quak/issues/199,
+https://git.eeqj.de/sneak/quak/issues/205 and
+https://git.eeqj.de/sneak/quak/issues/206. The check of quak against a live Ente
 account, https://git.eeqj.de/sneak/quak/issues/187, needs an account only sneak
 has, so it waits on him.
 

src/backup.ts

@@ -274,13 +274,14 @@ const rebuildSymlink = (linkPath: string, target: string): void => {
 // name is used as is unless another entry would get the same name, ignoring
 // case (two names that differ only in case are one entry on a case-insensitive
 // file system), or it is too long for a file name; then it gets ` (<id>)`,
-// before the extension when `beforeExtension` is set, with the name before it
-// cut short as far as it must be to fit. With `withJSON`, each entry also has
-// the JSON file `<name>.json` beside it, as an album does: a name then leaves
-// room for `.json`, and one that is another entry's JSON name gets its ID
-// added too. A name with an ID added can match another entry's own name
-// (`IMG (6).JPG`), so this repeats until no name is shared. IDs are stable, so
-// the names are too.
+// right before the extension when `beforeExtension` is set. To fit, the part
+// before the ID is cut short as far as it must be, and once nothing is left of
+// it, so is the extension. With `withJSON`, each entry also has the JSON file
+// `<name>.json` beside it, as an album does: a name then leaves room for
+// `.json`, and one that is another entry's JSON name gets its ID added too.
+// Two names with different IDs added never match, but one can match another
+// entry's own name (`IMG (6).JPG`), so this repeats until no name is shared.
+// IDs are stable, so the names are too.
 const uniqueNames = (
     entries: { id: number; name: string }[],
     opts: { beforeExtension?: boolean; withJSON?: boolean },
@@ -288,11 +289,9 @@ const uniqueNames = (
     const maxBytes = MAX_NAME_BYTES - (opts.withJSON ? ".json".length : 0);
     const withID = (id: number, name: string): string => {
         const tag = ` (${id})`;
-        let ext = opts.beforeExtension ? extname(name) : "";
-        // An extension too long to leave room for the ID is cut short with
-        // the rest of the name.
-        if (Buffer.byteLength(tag + ext) > maxBytes) ext = "";
-        const stem = name.slice(0, name.length - ext.length);
+        const fullExt = opts.beforeExtension ? extname(name) : "";
+        const stem = name.slice(0, name.length - fullExt.length);
+        const ext = shortenToBytes(fullExt, maxBytes - Buffer.byteLength(tag));
         const room = maxBytes - Buffer.byteLength(tag + ext);
         return shortenToBytes(stem, room) + tag + ext;
     };

test/cli/backup.test.ts

@@ -1703,31 +1703,6 @@ describe("backup album folders", () => {
         expect(readLedger(outDir).files["5"]).toMatchObject({ attempts: 2 });
     });
 
-    // The extension of this title is 303 bytes, so the ID cannot go before
-    // it, and the whole title is cut short with the ID at its end. The
-    // extension holds a "-", so the original is saved with `.bin`, a name
-    // that fits.
-    it("cuts a title short, extension and all, when its extension leaves no room for the ID", async () => {
-        const outDir = join(root, "backup");
-        const lib = libraryOf([
-            {
-                collection: collection(10, "Trip"),
-                files: [file(1, 10, `a.${"L".repeat(300)}-x`)],
-            },
-        ]);
-
-        const result = await runBackup(lib, { downloadDirectory: outDir });
-
-        const link = `a.${"L".repeat(249)} (1)`;
-        expect(Buffer.byteLength(link)).toBe(255);
-        expect(result.failed).toBe(0);
-        expect(tree(outDir)).toEqual([
-            "Trip/",
-            `Trip/${link} -> ${linkTo("1.bin")}`,
-            "Trip.json",
-        ]);
-    });
-
     // The user has put a file in collections/ with the name of the album
     // Trip's folder, so the folder cannot be made.
     it("goes on to the next album when an album's folder cannot be made, and lists it as failed", async () => {
@@ -1762,6 +1737,62 @@ describe("backup album folders", () => {
         expect(readLedger(outDir).files["5"]).toMatchObject({ attempts: 1 });
     });
 
+    // The extension of this title is 303 bytes, so it leaves no room for the
+    // ID: nothing is left of the name before the ID, and the extension is cut
+    // short after it. The extension holds a "-", so the original is saved
+    // with `.bin`, a name that fits.
+    it("cuts the extension of a title short when it leaves no room for the ID", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [file(1, 10, `a.${"L".repeat(300)}-x`)],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        const link = ` (1).${"L".repeat(250)}`;
+        expect(Buffer.byteLength(link)).toBe(255);
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Trip/",
+            `Trip/${link} -> ${linkTo("1.bin")}`,
+            "Trip.json",
+        ]);
+    });
+
+    // Files 1 and 3 share a title, so each gets its ID before the
+    // extension. File 2's title is too long, and its extension leaves no
+    // room for the ID. Were the ID put at the end of file 2's title cut
+    // short, its link would have file 1's name, and the link made second
+    // would replace the first.
+    it("keeps names unique when a title's extension leaves no room for the ID", async () => {
+        const outDir = join(root, "backup");
+        const shared = `x.${"Q".repeat(245)} (2)`;
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(1, 10, shared),
+                    file(2, 10, `x (1).${"Q".repeat(250)}-`),
+                    file(3, 10, shared),
+                ],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Trip/",
+            `Trip/ (2).${"Q".repeat(250)} -> ${linkTo("2.bin")}`,
+            `Trip/x (1).${"Q".repeat(245)} (2) -> ${linkTo("1.bin")}`,
+            `Trip/x (3).${"Q".repeat(245)} (2) -> ${linkTo("3.bin")}`,
+            "Trip.json",
+        ]);
+    });
+
     it("changes nothing on a second run over an unchanged account", async () => {
         const outDir = join(root, "backup");
         const lib = libraryOf([