feat(primitives): implement instant type

packages/primitives/src/index.ts

@@ -2,10 +2,11 @@
  * FHIR Primitive Runtime Types
  */
 
-import { BooleanType, boolean } from "./boolean";
 import { Base64BinaryType, base64binary } from "./base64binary";
+import { BooleanType, boolean } from "./boolean";
 import { CanonicalType, canonical } from "./canonical";
 import { DecimalType, decimal } from "./decimal";
+import { InstantType, instant } from "./instant";
 import { IntegerType, integer } from "./integer";
 import { StringType, string } from "./string";
 import { URIType, uri } from "./uri";
@@ -20,6 +21,8 @@ export {
   CanonicalType,
   decimal,
   DecimalType,
+  instant,
+  InstantType,
   integer,
   IntegerType,
   string,

packages/primitives/src/instant.ts

@@ -0,0 +1,21 @@
+/**
+ * Instant FHIR Primitive Runtime Type
+ */
+
+import { Type, success, failure, identity } from "io-ts";
+
+const INSTANT_REGEX = /([0-9]([0-9]([0-9][1-9]|[1-9]0)|[1-9]00)|[1-9]000)-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])T([01][0-9]|2[0-3]):[0-5][0-9]:([0-5][0-9]|60)(\.[0-9]+)?(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))/;
+
+export class InstantType extends Type<string> {
+  readonly _tag: "InstantType" = "InstantType";
+  constructor() {
+    super(
+      "instant",
+      (m): m is string => typeof m === "string" && INSTANT_REGEX.test(m),
+      (m, c) => (this.is(m) ? success(m) : failure(m, c)),
+      identity
+    );
+  }
+}
+
+export const instant = new InstantType();

packages/primitives/test/instant.test.ts

@@ -0,0 +1,38 @@
+/**
+ * Tests for Instant Runtime Type
+ */
+
+import { instant } from "../src";
+import { assertSuccess, assertFailure, assertStrictEqual } from "./helpers";
+
+describe("InstantType", () => {
+  it("should succeed validating a valid value", () => {
+    const T = instant;
+    assertSuccess(T.decode("2015-02-07T13:28:17.239+02:00"));
+  });
+
+  it("should return the same reference if validation succeeded and nothing changed", () => {
+    const T = instant;
+    const value = "2015-02-07T13:28:17.239+02:00";
+    assertStrictEqual(T.decode(value), value);
+  });
+
+  it("should fail validating an invalid value", () => {
+    const T = instant;
+    assertFailure(T.decode(2), ["Invalid value 2 supplied to : instant"]);
+  });
+
+  it("should fail validating non YYYY-MM-DDThh:mm:ss.sss+zz:zz formatted date", () => {
+    const T = instant;
+    assertFailure(T.decode("Mon Jan 21 2019 10:55:23 GMT-0600"), [
+      'Invalid value "Mon Jan 21 2019 10:55:23 GMT-0600" supplied to : instant'
+    ]);
+  });
+
+  it("should type guard", () => {
+    const T = instant;
+    expect(T.is("2015-02-07T13:28:17.239+02:00")).toEqual(true);
+    expect(T.is(true)).toEqual(false);
+    expect(T.is(undefined)).toEqual(false);
+  });
+});