feat: string transformer

src/transformers/string.spec.ts

@@ -0,0 +1,79 @@
+import { Type } from "@sinclair/typebox";
+import { expect, it } from "vitest";
+import type { Options } from "yargs";
+
+import { getStringOption } from "./string";
+
+it("should transform TString to yargs option", () => {
+  const schema = Type.String();
+
+  const result = getStringOption(schema);
+
+  expect(result).toEqual({
+    type: "string",
+    requiresArg: true,
+  });
+});
+
+it("should transform TString with truthy default value to yargs option", () => {
+  const schema = Type.String({ default: "foo" });
+
+  const result = getStringOption(schema);
+
+  expect(result).toEqual({
+    type: "string",
+    requiresArg: false,
+    default: "foo",
+  });
+});
+
+it("should transform TString with falsy default value to yargs option", () => {
+  const schema = Type.String({ default: "" });
+
+  const result = getStringOption(schema);
+
+  expect(result).toEqual({
+    type: "string",
+    requiresArg: false,
+    default: "",
+  });
+});
+
+it("should transform TString with description to yargs option", () => {
+  const schema = Type.String({ description: "foo" });
+
+  const result = getStringOption(schema);
+
+  expect(result).toEqual({
+    type: "string",
+    requiresArg: true,
+    description: "foo",
+  });
+});
+
+it("should transform TString with override to yargs option", () => {
+  const schema = Type.String();
+  const overwrite: Options = {
+    requiresArg: false,
+    alias: "aliased",
+  };
+
+  const result = getStringOption(schema, overwrite);
+
+  expect(result).toEqual({
+    type: "string",
+    requiresArg: false,
+    alias: "aliased",
+  });
+});
+
+it("should detect if it is optional", () => {
+  const schema = Type.Optional(Type.String());
+
+  const result = getStringOption(schema);
+
+  expect(result).toEqual({
+    type: "string",
+    requiresArg: false,
+  });
+});

src/transformers/string.ts

@@ -0,0 +1,22 @@
+import { type TString, TypeGuard } from "@sinclair/typebox";
+import type { Options } from "yargs";
+
+export function getStringOption(
+  schema: TString,
+  override: Options = {},
+): Options {
+  const hasDefaultValue = schema.default !== undefined;
+  const options = {
+    type: "string" as const,
+    requiresArg: !TypeGuard.IsOptional(schema) && !hasDefaultValue,
+  };
+
+  if (hasDefaultValue)
+    Object.assign(options, { default: schema.default as string });
+  if (schema.description)
+    Object.assign(options, { description: schema.description });
+
+  Object.assign(options, override);
+
+  return options;
+}