Fix "Readwise Syncs.md" JSON parse error when base folder is vault root

[gregbot-rw]

Summary

Fixes the Obsidian plugin error reported in DevHelp:

error writing Readwise Syncs.md: SyntaxError: No number after minus sign in JSON at position 1 (line 1 column 2)

Highlights export fine, but the sync notification file fails to write.

Root cause

In downloadExport (src/main.ts), each export ZIP entry is classified as either a JSON document file (→ JSON.parse) or the special plain-markdown sync-log file Readwise Syncs.md (→ used verbatim). The classification compares the normalized processedFileName against an un-normalized expected path:

const isReadwiseSyncFile = processedFileName === `${this.settings.readwiseDir}/${READWISE_SYNC_FILENAME}.md`;

processedFileName is built with normalizePath(...), which strips leading slashes. When the user's base folder (readwiseDir) is the vault root ("/" or ""), the right-hand side keeps a stray leading slash ("/Readwise Syncs.md") while processedFileName becomes "Readwise Syncs.md". They no longer match, so the markdown sync file falls into the else branch and is fed to JSON.parse. Because the rendered notification commonly begins with - (e.g. - [[2026-05-28]] ...), V8 throws No number after minus sign in JSON at position 1.

Per-document files are unaffected because they are genuine .json entries — which is why highlights export fine while only the sync notification errors.

Fix

Normalize both sides of the comparison via a small pure helper readwiseSyncFilePath(readwiseDir, normalizePath) in src/paths.ts, and use it in main.ts. No behavior change for the default Readwise base folder or nested folders; the root-folder case is now correctly recognized.

Reproduction (exact user error)

A standalone repro of Obsidian's normalizePath + the original comparison reproduces the user's error verbatim and confirms the fix:

readwiseDir = "/"   BEFORE: isReadwiseSyncFile=false → SyntaxError: No number after minus sign in JSON at position 1 (line 1 column 2)
readwiseDir = "/"   AFTER : isReadwiseSyncFile=true  → no error
readwiseDir = ""    BEFORE: isReadwiseSyncFile=false → SyntaxError: No number after minus sign in JSON at position 1 (line 1 column 2)
readwiseDir = ""    AFTER : isReadwiseSyncFile=true  → no error
readwiseDir = "Readwise"        BEFORE/AFTER: isReadwiseSyncFile=true (unchanged)
readwiseDir = "Notes/Readwise"  BEFORE/AFTER: isReadwiseSyncFile=true (unchanged)

Test plan

• npm test — full suite passes (10/10), including new tests/paths.test.js covering root, default, and nested base folders
• npm run build — production rollup bundle builds clean
• Manual: set base folder to vault root in Obsidian, run a sync, confirm Readwise Syncs.md is written without error

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