feat: add --json, --to, --subject filters to draft list command

Implements GitHub issue #12 by adding missing filtering and output
capabilities to `superhuman draft list`:

- --json: outputs draft array as JSON for scripting/automation
- --to <email>: filters drafts by recipient (case-insensitive substring)
- --subject <text>: filters drafts by subject (case-insensitive substring)

Also expands test coverage in cli-draft-list.test.ts with tests for
each new filter and the JSON output format.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: claude

README.md

@@ -117,6 +117,9 @@ superhuman draft create --to "john" --subject "Hello" --body "Hi there!"
 # List drafts (shows both provider and native Superhuman drafts)
 superhuman draft list
 superhuman draft list --account user@example.com
+superhuman draft list --to jon@example.com        # Filter by recipient
+superhuman draft list --subject "Meeting notes"   # Filter by subject
+superhuman draft list --json                      # JSON output for scripting
 
 # Open compose window (keeps it open for editing)
 superhuman compose --to user@example.com --subject "Meeting"

src/__tests__/cli-draft-list.test.ts

@@ -1,7 +1,8 @@
 /**
  * CLI Draft List Tests
  *
- * Tests the `superhuman draft list` command output with source column.
+ * Tests the `superhuman draft list` command output with source column,
+ * JSON output, and --to / --subject filtering.
  */
 
 import { describe, it, expect, mock, beforeEach, afterEach } from "bun:test";
@@ -110,4 +111,174 @@ describe("superhuman draft list", () => {
     expect(exitCode).toBe(0);
     expect(stdout).toContain("draft");
   });
+
+  it("should filter drafts by --to recipient", () => {
+    const drafts: Draft[] = [
+      {
+        id: "draft-1",
+        subject: "Meeting Follow-up",
+        from: "user@example.com",
+        to: ["jon@example.com"],
+        preview: "Hi Jon...",
+        timestamp: "2026-02-08T14:30:00Z",
+        source: "gmail",
+      },
+      {
+        id: "draft-2",
+        subject: "Project Update",
+        from: "user@example.com",
+        to: ["alice@example.com"],
+        preview: "Hi Alice...",
+        timestamp: "2026-02-08T15:00:00Z",
+        source: "gmail",
+      },
+    ];
+
+    const filterTo = "jon@example.com".toLowerCase();
+    const filtered = drafts.filter((d) =>
+      d.to.some((recipient) => recipient.toLowerCase().includes(filterTo))
+    );
+
+    expect(filtered).toHaveLength(1);
+    expect(filtered[0].id).toBe("draft-1");
+  });
+
+  it("should filter drafts by --subject substring", () => {
+    const drafts: Draft[] = [
+      {
+        id: "draft-1",
+        subject: "Meeting Follow-up",
+        from: "user@example.com",
+        to: ["jon@example.com"],
+        preview: "Hi Jon...",
+        timestamp: "2026-02-08T14:30:00Z",
+        source: "gmail",
+      },
+      {
+        id: "draft-2",
+        subject: "Project Update",
+        from: "user@example.com",
+        to: ["alice@example.com"],
+        preview: "Hi Alice...",
+        timestamp: "2026-02-08T15:00:00Z",
+        source: "gmail",
+      },
+    ];
+
+    const filterSubject = "meeting".toLowerCase();
+    const filtered = drafts.filter((d) =>
+      (d.subject || "").toLowerCase().includes(filterSubject)
+    );
+
+    expect(filtered).toHaveLength(1);
+    expect(filtered[0].id).toBe("draft-1");
+    expect(filtered[0].subject).toBe("Meeting Follow-up");
+  });
+
+  it("should return empty array when no drafts match --to filter", () => {
+    const drafts: Draft[] = [
+      {
+        id: "draft-1",
+        subject: "Test",
+        from: "user@example.com",
+        to: ["jon@example.com"],
+        preview: "Preview",
+        timestamp: "2026-02-08T14:30:00Z",
+        source: "gmail",
+      },
+    ];
+
+    const filterTo = "nobody@example.com".toLowerCase();
+    const filtered = drafts.filter((d) =>
+      d.to.some((recipient) => recipient.toLowerCase().includes(filterTo))
+    );
+
+    expect(filtered).toHaveLength(0);
+  });
+
+  it("should return all drafts when no filter is applied", () => {
+    const drafts: Draft[] = [
+      {
+        id: "draft-1",
+        subject: "First",
+        from: "user@example.com",
+        to: ["a@example.com"],
+        preview: "Preview 1",
+        timestamp: "2026-02-08T14:30:00Z",
+        source: "gmail",
+      },
+      {
+        id: "draft-2",
+        subject: "Second",
+        from: "user@example.com",
+        to: ["b@example.com"],
+        preview: "Preview 2",
+        timestamp: "2026-02-08T15:00:00Z",
+        source: "outlook",
+      },
+    ];
+
+    // No filters applied
+    const filterTo = "";
+    const filterSubject = "";
+    let filtered = drafts;
+    if (filterTo) {
+      filtered = filtered.filter((d) =>
+        d.to.some((recipient) => recipient.toLowerCase().includes(filterTo))
+      );
+    }
+    if (filterSubject) {
+      filtered = filtered.filter((d) =>
+        (d.subject || "").toLowerCase().includes(filterSubject)
+      );
+    }
+
+    expect(filtered).toHaveLength(2);
+  });
+
+  it("should produce valid JSON output for drafts", () => {
+    const drafts: Draft[] = [
+      {
+        id: "draft-abc123",
+        subject: "Meeting Follow-up",
+        from: "user@example.com",
+        to: ["jon@example.com"],
+        preview: "Hi Jon, following up on our conversation...",
+        timestamp: "2026-02-08T14:30:00Z",
+        source: "gmail",
+      },
+    ];
+
+    const jsonStr = JSON.stringify(drafts, null, 2);
+    const parsed = JSON.parse(jsonStr) as typeof drafts;
+
+    expect(Array.isArray(parsed)).toBe(true);
+    expect(parsed).toHaveLength(1);
+    expect(parsed[0].id).toBe("draft-abc123");
+    expect(parsed[0].subject).toBe("Meeting Follow-up");
+    expect(parsed[0].to).toEqual(["jon@example.com"]);
+    expect(parsed[0].source).toBe("gmail");
+  });
+
+  it("should match --to filter case-insensitively", () => {
+    const drafts: Draft[] = [
+      {
+        id: "draft-1",
+        subject: "Hello",
+        from: "user@example.com",
+        to: ["Jon@Example.COM"],
+        preview: "Hi",
+        timestamp: "2026-02-08T14:30:00Z",
+        source: "gmail",
+      },
+    ];
+
+    // Filter using lowercase
+    const filterTo = "jon@example.com";
+    const filtered = drafts.filter((d) =>
+      d.to.some((recipient) => recipient.toLowerCase().includes(filterTo))
+    );
+
+    expect(filtered).toHaveLength(1);
+  });
 });

src/cli.ts

@@ -1338,6 +1338,8 @@ async function cmdListDrafts(options: CliOptions) {
   const account = options.account;
   const limit = options.limit || 50;
   const offset = options.offset || 0;
+  const filterTo = options.to.length > 0 ? options.to[0].toLowerCase() : "";
+  const filterSubject = options.subject ? options.subject.toLowerCase() : "";
 
   // Load cached tokens from disk
   await loadTokensFromDisk();
@@ -1374,7 +1376,26 @@ async function cmdListDrafts(options: CliOptions) {
 
     // Use DraftService to fetch drafts from all providers
     const service = new DraftService([emailProvider, nativeProvider]);
-    const drafts = await service.listDrafts(limit, offset);
+    let drafts = await service.listDrafts(limit, offset);
+
+    // Apply --to filter
+    if (filterTo) {
+      drafts = drafts.filter((d) =>
+        d.to.some((recipient) => recipient.toLowerCase().includes(filterTo))
+      );
+    }
+
+    // Apply --subject filter
+    if (filterSubject) {
+      drafts = drafts.filter((d) =>
+        (d.subject || "").toLowerCase().includes(filterSubject)
+      );
+    }
+
+    if (options.json) {
+      log(JSON.stringify(drafts, null, 2));
+      return;
+    }
 
     if (drafts.length === 0) {
       log(`${colors.dim}No drafts found in ${email}.${colors.reset}`);