fix: preserve blank lines for newline chunking (#1645) (thanks @tyler6204)

CHANGELOG.md

@@ -14,6 +14,7 @@ Docs: https://docs.clawd.bot
 - Docs: add Bedrock EC2 instance role setup + IAM steps. (#1625) Thanks @sergical. https://docs.clawd.bot/bedrock
 - Exec approvals: forward approval prompts to chat with `/approve` for all channels (including plugins). (#1621) Thanks @czekaj. https://docs.clawd.bot/tools/exec-approvals https://docs.clawd.bot/tools/slash-commands
 - Gateway: expose config.patch in the gateway tool with safe partial updates + restart sentinel. (#1653) Thanks @Glucksberg.
+- BlueBubbles: add newline chunking mode option for streaming. (#1645) Thanks @tyler6204.
 
 ### Fixes
 - BlueBubbles: keep part-index GUIDs in reply tags when short IDs are missing.

extensions/bluebubbles/src/types.ts

@@ -38,7 +38,7 @@ export type BlueBubblesAccountConfig = {
   dms?: Record<string, unknown>;
   /** Outbound text chunk size (chars). Default: 4000. */
   textChunkLimit?: number;
-  /** Chunking mode: "newline" (default) splits on every newline; "length" splits by size. */
+  /** Chunking mode: "length" (default) splits by size; "newline" splits on every newline. */
   chunkMode?: "length" | "newline";
   blockStreaming?: boolean;
   /** Merge streamed block replies before sending. */

src/auto-reply/chunk.test.ts

@@ -246,10 +246,10 @@ describe("chunkByNewline", () => {
     expect(chunks).toEqual(["Line one", "Line two", "Line three"]);
   });
 
-  it("filters empty lines", () => {
+  it("preserves blank lines by folding into the next chunk", () => {
     const text = "Line one\n\n\nLine two\n\nLine three";
     const chunks = chunkByNewline(text, 1000);
-    expect(chunks).toEqual(["Line one", "Line two", "Line three"]);
+    expect(chunks).toEqual(["Line one", "\n\nLine two", "\nLine three"]);
   });
 
   it("trims whitespace from lines", () => {
@@ -258,6 +258,12 @@ describe("chunkByNewline", () => {
     expect(chunks).toEqual(["Line one", "Line two"]);
   });
 
+  it("preserves leading blank lines on the first chunk", () => {
+    const text = "\n\nLine one\nLine two";
+    const chunks = chunkByNewline(text, 1000);
+    expect(chunks).toEqual(["\n\nLine one", "Line two"]);
+  });
+
   it("falls back to length-based for long lines", () => {
     const text = "Short line\n" + "a".repeat(50) + "\nAnother short";
     const chunks = chunkByNewline(text, 20);

src/auto-reply/chunk.ts

@@ -116,19 +116,34 @@ export function resolveChunkMode(
  */
 export function chunkByNewline(text: string, maxLineLength: number): string[] {
   if (!text) return [];
+  if (maxLineLength <= 0) return text.trim() ? [text] : [];
   const lines = text.split("\n");
   const chunks: string[] = [];
+  let pendingBlankLines = 0;
 
   for (const line of lines) {
     const trimmed = line.trim();
-    if (!trimmed) continue; // skip empty lines
+    if (!trimmed) {
+      pendingBlankLines += 1;
+      continue;
+    }
 
-    if (trimmed.length <= maxLineLength) {
-      chunks.push(trimmed);
-    } else {
-      // Long line: fall back to length-based chunking
-      const subChunks = chunkText(trimmed, maxLineLength);
-      chunks.push(...subChunks);
+    const maxPrefix = Math.max(0, maxLineLength - 1);
+    const cappedBlankLines = pendingBlankLines > 0 ? Math.min(pendingBlankLines, maxPrefix) : 0;
+    const prefix = cappedBlankLines > 0 ? "\n".repeat(cappedBlankLines) : "";
+    pendingBlankLines = 0;
+
+    if (trimmed.length + prefix.length <= maxLineLength) {
+      chunks.push(prefix + trimmed);
+      continue;
+    }
+
+    const firstLimit = Math.max(1, maxLineLength - prefix.length);
+    const first = trimmed.slice(0, firstLimit);
+    chunks.push(prefix + first);
+    const remaining = trimmed.slice(firstLimit);
+    if (remaining) {
+      chunks.push(...chunkText(remaining, maxLineLength));
     }
   }