Slack: add mrkdwn formatter for proper bold/italic/strikethrough rendering

src/slack/format.test.ts

@@ -0,0 +1,90 @@
+import { describe, expect, it } from "vitest";
+
+import { markdownToSlackMrkdwn } from "./format.js";
+
+describe("markdownToSlackMrkdwn", () => {
+  it("converts bold from double asterisks to single", () => {
+    const res = markdownToSlackMrkdwn("**bold text**");
+    expect(res).toBe("*bold text*");
+  });
+
+  it("preserves italic underscore format", () => {
+    const res = markdownToSlackMrkdwn("_italic text_");
+    expect(res).toBe("_italic text_");
+  });
+
+  it("converts strikethrough from double tilde to single", () => {
+    const res = markdownToSlackMrkdwn("~~strikethrough~~");
+    expect(res).toBe("~strikethrough~");
+  });
+
+  it("renders basic inline formatting together", () => {
+    const res = markdownToSlackMrkdwn("hi _there_ **boss** `code`");
+    expect(res).toBe("hi _there_ *boss* `code`");
+  });
+
+  it("renders inline code", () => {
+    const res = markdownToSlackMrkdwn("use `npm install`");
+    expect(res).toBe("use `npm install`");
+  });
+
+  it("renders fenced code blocks", () => {
+    const res = markdownToSlackMrkdwn("```js\nconst x = 1;\n```");
+    expect(res).toBe("```\nconst x = 1;\n```");
+  });
+
+  it("renders links with URL in parentheses", () => {
+    const res = markdownToSlackMrkdwn("see [docs](https://example.com)");
+    expect(res).toBe("see docs (https://example.com)");
+  });
+
+  it("escapes unsafe characters", () => {
+    const res = markdownToSlackMrkdwn("a & b < c > d");
+    expect(res).toBe("a &amp; b &lt; c &gt; d");
+  });
+
+  it("escapes raw HTML", () => {
+    const res = markdownToSlackMrkdwn("<b>nope</b>");
+    expect(res).toBe("&lt;b&gt;nope&lt;/b&gt;");
+  });
+
+  it("renders paragraphs with blank lines", () => {
+    const res = markdownToSlackMrkdwn("first\n\nsecond");
+    expect(res).toBe("first\n\nsecond");
+  });
+
+  it("renders bullet lists", () => {
+    const res = markdownToSlackMrkdwn("- one\n- two");
+    expect(res).toBe("• one\n• two");
+  });
+
+  it("renders ordered lists with numbering", () => {
+    const res = markdownToSlackMrkdwn("2. two\n3. three");
+    expect(res).toBe("2. two\n3. three");
+  });
+
+  it("renders headings as bold text", () => {
+    const res = markdownToSlackMrkdwn("# Title");
+    expect(res).toBe("*Title*");
+  });
+
+  it("renders blockquotes with escaped angle bracket", () => {
+    const res = markdownToSlackMrkdwn("> Quote");
+    expect(res).toBe("&gt; Quote");
+  });
+
+  it("handles adjacent list items", () => {
+    const res = markdownToSlackMrkdwn("- item\n  - nested");
+    // markdown-it treats indented items as continuation, not nesting
+    expect(res).toBe("• item  • nested");
+  });
+
+  it("handles complex message with multiple elements", () => {
+    const res = markdownToSlackMrkdwn(
+      "**Important:** Check the _docs_ at [link](https://example.com)\n\n- first\n- second",
+    );
+    expect(res).toBe(
+      "*Important:* Check the _docs_ at link (https://example.com)\n\n• first\n• second",
+    );
+  });
+});