Add cart set/update/remove with bulk patch + fix cart clear (#7)

README.md

@@ -74,9 +74,14 @@ kronan logout                 Clear stored token
 kronan search <query>         Search for products
 kronan product <sku>          Product details by SKU
 
-kronan cart                   View cart
-kronan cart add <sku> [qty]   Add item to cart
-kronan cart clear             Clear cart
+kronan cart                              View cart
+kronan cart add <sku> [qty]              Add item to cart
+kronan cart set '<json>'                 Replace whole cart with JSON lines
+kronan cart update <sku|id> --quantity N Update one line (qty 0 removes)
+kronan cart update '<json-patch>'        Bulk update via JSON patch
+kronan cart remove <sku|id>              Remove a single line
+kronan cart clear                        Clear cart
+                                         (set/update/remove/clear support --dry-run)
 
 kronan orders                 Order history
 kronan order <token>          Specific order details
@@ -85,7 +90,32 @@ kronan lists                  View product lists
 kronan me                     Show current identity
 ```
 
-All commands support `--json` for structured output.
+All commands support `--json` for structured output. Cart mutation commands
+(`set`, `update`, `remove`, `clear`) also accept `--dry-run` to preview the
+resulting cart without calling the API.
+
+### Cart editing examples
+
+```bash
+# Replace the entire cart with a fixed set of lines
+kronan cart set '[{"sku":"02500188","quantity":3}]'
+kronan cart set '{"02500188":1,"100151784":2}'
+
+# Update a single line by SKU or numeric line id
+kronan cart update 02500188 --quantity 5
+kronan cart update 13065307 --quantity 0      # qty 0 removes the line
+
+# Bulk update: object/array of {sku:qty} as a patch.
+# Listed SKUs are set to the given qty (0 removes); unlisted lines are left
+# alone. SKUs not currently in the cart are added when qty > 0.
+kronan cart update '{"02500188":3,"100151784":0,"100224198":1}'
+
+# Remove a single line (shorthand for --quantity 0)
+kronan cart remove 02500188
+
+# Preview any of the above without hitting the API
+kronan cart update '{"02500188":3}' --dry-run --json
+```
 
 ## AI agent usage
 

src/api.ts

@@ -544,6 +544,12 @@ export async function addCheckoutLines(
 
 /**
  * Replace all checkout lines.
+ *
+ * Workaround for upstream API behaviour: `POST /checkout/lines/` with
+ * `{lines: [], replace: true}` is silently a no-op (returns the unchanged
+ * checkout instead of clearing it — see arnif/kronan-cli#7). When the caller
+ * asks for an empty cart we instead fetch the current lines and send each one
+ * back with `quantity: 0`, which the backend honours.
  */
 export async function replaceCheckoutLines(
   token: AuthToken,
@@ -553,7 +559,34 @@ export async function replaceCheckoutLines(
     substitution?: boolean;
   }>,
 ): Promise<PublicCheckout> {
-  return addCheckoutLines(token, lines, true);
+  if (lines.length > 0) {
+    return addCheckoutLines(token, lines, true);
+  }
+
+  const checkout = await getCheckout(token);
+  const existing = checkout?.lines ?? [];
+  if (existing.length === 0) {
+    // Cart already empty; nothing to do. Synthesize an empty checkout if the
+    // GET returned null (no active checkout).
+    return (
+      checkout ?? {
+        token: "",
+        lines: [],
+        total: 0,
+        subtotal: 0,
+        baggingFee: 0,
+        serviceFee: 0,
+        shippingFee: 0,
+        shippingFeeCutoff: 0,
+      }
+    );
+  }
+  const deletes = existing.map((line) => ({
+    sku: line.product?.sku ?? "",
+    quantity: 0,
+    substitution: line.substitution ?? true,
+  }));
+  return addCheckoutLines(token, deletes, true);
 }
 
 // --- Product Lists API Functions ---

src/cli.test.ts

@@ -12,6 +12,36 @@ describe("CLI", () => {
     expect(result).toContain("token");
   });
 
+  test("help lists cart set/update/remove commands", async () => {
+    const result = await $`bun src/index.ts help`.text();
+    expect(result).toContain("cart set");
+    expect(result).toContain("cart update");
+    expect(result).toContain("cart remove");
+    expect(result).toContain("--dry-run");
+  });
+
+  test("cart set without JSON argument errors", async () => {
+    const proc = Bun.spawn(["bun", "src/index.ts", "cart", "set"], {
+      stderr: "pipe",
+    });
+    const stderr = await new Response(proc.stderr).text();
+    expect(stderr).toContain("Usage: kronan cart set");
+  });
+
+  test("cart update without --quantity errors", async () => {
+    const proc = Bun.spawn(
+      ["bun", "src/index.ts", "cart", "update", "02500188"],
+      { stderr: "pipe" },
+    );
+    const stderr = await new Response(proc.stderr).text();
+    expect(stderr).toContain("--quantity");
+  });
+
+  test("help documents bulk cart update JSON form", async () => {
+    const result = await $`bun src/index.ts help`.text();
+    expect(result).toContain("json-patch");
+  });
+
   test("no arguments shows help", async () => {
     const result = await $`bun src/index.ts`.text();
     expect(result).toContain("kronan-cli");

src/commands/cart.test.ts

@@ -0,0 +1,74 @@
+import { describe, expect, test } from "bun:test";
+import { parseCartLinesJson } from "./cart.ts";
+
+describe("parseCartLinesJson", () => {
+  test("parses array of {sku, quantity}", () => {
+    const lines = parseCartLinesJson(
+      '[{"sku":"02500059","quantity":1},{"sku":"100151784","quantity":2}]',
+    );
+    expect(lines).toEqual([
+      { sku: "02500059", quantity: 1 },
+      { sku: "100151784", quantity: 2 },
+    ]);
+  });
+
+  test("preserves substitution when present in array form", () => {
+    const lines = parseCartLinesJson(
+      '[{"sku":"02500059","quantity":1,"substitution":false}]',
+    );
+    expect(lines).toEqual([
+      { sku: "02500059", quantity: 1, substitution: false },
+    ]);
+  });
+
+  test("parses object map {sku:quantity}", () => {
+    const lines = parseCartLinesJson('{"02500059":1,"100151784":2}');
+    expect(lines.length).toBe(2);
+    expect(lines).toEqual(
+      expect.arrayContaining([
+        { sku: "02500059", quantity: 1 },
+        { sku: "100151784", quantity: 2 },
+      ]),
+    );
+  });
+
+  test("rejects invalid JSON", () => {
+    expect(() => parseCartLinesJson("not json")).toThrow(/Invalid JSON/);
+  });
+
+  test("rejects negative quantities in array form", () => {
+    expect(() =>
+      parseCartLinesJson('[{"sku":"02500059","quantity":-1}]'),
+    ).toThrow(/non-negative integer/);
+  });
+
+  test("rejects negative quantities in map form", () => {
+    expect(() => parseCartLinesJson('{"02500059":-1}')).toThrow(
+      /non-negative integer/,
+    );
+  });
+
+  test("rejects non-integer quantities", () => {
+    expect(() =>
+      parseCartLinesJson('[{"sku":"02500059","quantity":1.5}]'),
+    ).toThrow(/non-negative integer/);
+  });
+
+  test("rejects missing sku", () => {
+    expect(() => parseCartLinesJson('[{"quantity":1}]')).toThrow(
+      /sku must be a non-empty string/,
+    );
+  });
+
+  test("rejects non-number map value", () => {
+    expect(() => parseCartLinesJson('{"02500059":"1"}')).toThrow(
+      /must be a number/,
+    );
+  });
+
+  test("rejects scalar JSON", () => {
+    expect(() => parseCartLinesJson("42")).toThrow(
+      /must be an array.*or an object map/,
+    );
+  });
+});