fix: preserve discord chunk whitespace

CHANGELOG.md

@@ -71,6 +71,7 @@
 - Security: bump `tar` to 7.5.3.
 - Models: align ZAI thinking toggles.
 - iMessage/Signal: include sender metadata for non-queued group messages. (#1059)
+- Discord: preserve whitespace when chunking long lines so message splits keep spacing intact.
 
 ## 2026.1.15
 

src/discord/chunk.test.ts

@@ -63,6 +63,27 @@ describe("chunkDiscordText", () => {
     }
   });
 
+  it("preserves whitespace when splitting long lines", () => {
+    const text = Array.from({ length: 40 }, () => "word").join(" ");
+    const chunks = chunkDiscordText(text, { maxChars: 20, maxLines: 50 });
+    expect(chunks.length).toBeGreaterThan(1);
+    expect(chunks.join("")).toBe(text);
+  });
+
+  it("preserves mixed whitespace across chunk boundaries", () => {
+    const text = "alpha  beta\tgamma   delta epsilon  zeta";
+    const chunks = chunkDiscordText(text, { maxChars: 12, maxLines: 50 });
+    expect(chunks.length).toBeGreaterThan(1);
+    expect(chunks.join("")).toBe(text);
+  });
+
+  it("keeps leading whitespace when splitting long lines", () => {
+    const text = "    indented line with words that force splits";
+    const chunks = chunkDiscordText(text, { maxChars: 14, maxLines: 50 });
+    expect(chunks.length).toBeGreaterThan(1);
+    expect(chunks.join("")).toBe(text);
+  });
+
   it("keeps reasoning italics balanced across chunks", () => {
     const body = Array.from({ length: 25 }, (_, i) => `${i + 1}. line`).join("\n");
     const text = `Reasoning:\n_${body}_`;

src/discord/chunk.ts

@@ -76,8 +76,8 @@ function splitLongLine(
     }
     if (breakIdx <= 0) breakIdx = limit;
     out.push(remaining.slice(0, breakIdx));
-    const brokeOnSeparator = breakIdx < remaining.length && /\s/.test(remaining[breakIdx]);
-    remaining = remaining.slice(breakIdx + (brokeOnSeparator ? 1 : 0));
+    // Keep the separator for the next segment so words don't get glued together.
+    remaining = remaining.slice(breakIdx);
   }
   if (remaining.length) out.push(remaining);
   return out;