test: tighten shared text chunking coverage

src/shared/chat-content.test.ts

@@ -12,6 +12,7 @@ describe("shared/chat-content", () => {
         { type: "text", text: " hello " },
         { type: "image_url", image_url: "https://example.com" },
         { type: "text", text: "world" },
+        { text: "ignored without type" },
         null,
       ]),
     ).toBe("hello world");
@@ -37,6 +38,18 @@ describe("shared/chat-content", () => {
         },
       ),
     ).toBe("hello\nworld");
+
+    expect(
+      extractTextFromChatContent(
+        [
+          { type: "text", text: "keep" },
+          { type: "text", text: "drop" },
+        ],
+        {
+          sanitizeText: (text) => (text === "drop" ? "   " : text),
+        },
+      ),
+    ).toBe("keep");
   });
 
   it("returns null for unsupported or empty content", () => {

src/shared/text-chunking.test.ts

@@ -5,12 +5,14 @@ describe("shared/text-chunking", () => {
   it("returns empty for blank input and the full text when under limit", () => {
     expect(chunkTextByBreakResolver("", 10, () => 5)).toEqual([]);
     expect(chunkTextByBreakResolver("hello", 10, () => 2)).toEqual(["hello"]);
+    expect(chunkTextByBreakResolver("hello", 0, () => 2)).toEqual(["hello"]);
   });
 
   it("splits at resolver-provided breakpoints and trims separator boundaries", () => {
     expect(
       chunkTextByBreakResolver("alpha beta gamma", 10, (window) => window.lastIndexOf(" ")),
     ).toEqual(["alpha", "beta gamma"]);
+    expect(chunkTextByBreakResolver("abcd efgh", 4, () => 4)).toEqual(["abcd", "efgh"]);
   });
 
   it("falls back to hard limits for invalid break indexes", () => {
@@ -28,4 +30,11 @@ describe("shared/text-chunking", () => {
       chunkTextByBreakResolver("word     next", 5, (window) => window.lastIndexOf(" ")),
     ).toEqual(["word", "next"]);
   });
+
+  it("trims trailing whitespace from emitted chunks before continuing", () => {
+    expect(chunkTextByBreakResolver("abc   def", 6, (window) => window.lastIndexOf(" "))).toEqual([
+      "abc",
+      "def",
+    ]);
+  });
 });