feat: custom tool renderers

tests/tool-errors.test.ts

@@ -0,0 +1,33 @@
+import { expect, test } from "bun:test";
+import { readStoredToolError, serializeToolError } from "../utils/tool-errors";
+
+const validationError = "Invalid input for tool search: Type validation failed: Value: {\"query\":123}.\nError message: [{\"code\":\"custom\"}]";
+
+test("tool Error instances persist their message, not an empty JSON object", () => {
+    expect(serializeToolError(new Error(validationError))).toBe(validationError);
+    expect(serializeToolError(validationError)).toBe(validationError);
+    expect(serializeToolError({ reason: "invalid input" })).toBe('{"reason":"invalid input"}');
+});
+
+test("text validation errors remain text on history replay", () => {
+    expect(readStoredToolError({ type: "text", value: validationError })).toEqual({
+        type: "error-text",
+        value: validationError,
+    });
+});
+
+test("legacy mislabeled JSON errors cannot break subsequent prompts", () => {
+    expect(readStoredToolError({ type: "json", value: validationError })).toEqual({
+        type: "error-text",
+        value: validationError,
+    });
+});
+
+test("preserves actual JSON errors and handles missing errors", () => {
+    expect(readStoredToolError({ type: "json", value: '{"reason":"bad input"}' })).toEqual({
+        type: "error-json",
+        value: { reason: "bad input" },
+    });
+    expect(readStoredToolError(null).type).toBe("error-text");
+    expect(readStoredToolError(undefined).type).toBe("error-text");
+});