feat(fhir-ts-codegen): rewrite to target io-ts

Rewrite the codegen to target io-ts runtime types rather than TypeScript
interfaces. Refactored to use lighter-weight CLI library. Generating
code through string interpolation rather than the TypeScript AST.

packages/fhir-ts-codegen/README.md

@@ -1,6 +1,6 @@
 # fhir-ts-codegen
 
-FHIR TypeScript definitions generator.
+Generate [io-ts](https://github.com/gcanti/io-ts) runtime types from FHIR StructureDefinitions.
 
 ## Disclaimer
 
@@ -15,33 +15,21 @@ npm install @tangdrew/fhir-ts-codegen -g
 ## Usage
 
 ```sh
-fhir-ts-codegen <pattern> <output-directory>
+Usage: fhir-ts-codegen [options]
+
+Options:
+  -i, --input <dir>   input pattern to StructureDefinitions
+  -o, --output <dir>  path to output directory
+  -V, --version       output the version number
+  -h, --help          output usage information
 ```
 
 Example:
 
 ```sh
-fhir-ts-codegen "structure-defintions/**.profile.json" "types"
+fhir-ts-codegen "structure-definitions/**.profile.json" "types"
 ```
 
-## Roadmap
-
-- Resource Definitions
-  - [x] Interface declaration from snapshot
-  - [x] Property names
-  - [x] Property type names
-  - [x] Optional properties
-  - [x] Array properties
-  - [x] JSDoc comments
-  - [x] Backbone Element properties
-  - [ ] Interface declaration from differential
-  - [ ] Default values
-  - [x] Content reference
-- Primitive types
-  - [x] Type aliases
-  - [x] Extensions
-- CLI options
-
 ## License
 
 [MIT licensed](./LICENSE).

packages/fhir-ts-codegen/bin/index.js

@@ -0,0 +1,19 @@
+#!/usr/bin/env node
+
+const program = require("commander");
+const config = require("../package.json");
+const { Generator } = require("../dist");
+
+program
+  .name("fhir-ts-codegen")
+  .option("-i, --input <dir>", "input pattern to StructureDefinitions")
+  .option("-o, --output <dir>", "path to output directory")
+  .version(config.version)
+  .parse(process.argv);
+
+if (program.input && program.output) {
+  const generator = new Generator(program.input, program.output);
+  generator.run();
+} else {
+  program.help()
+}

packages/fhir-ts-codegen/lib/conformance.ts

@@ -0,0 +1,60 @@
+/**
+ * FHIR Conformance Types
+ */
+
+export enum FHIRPrimitives {
+  base64binary = "base64binary",
+  boolean = "boolean",
+  canonical = "canonical",
+  code = "code",
+  date = "date",
+  dateTime = "dateTime",
+  decimal = "decimal",
+  id = "id",
+  instant = "instant",
+  integer = "integer",
+  markdown = "markdown",
+  oid = "oid",
+  positiveInt = "positiveInt",
+  string = "string",
+  time = "time",
+  unsignedInt = "unsignedInt",
+  uri = "uri",
+  url = "url",
+  uuid = "uuid"
+}
+
+export interface StructureDefinition {
+  resourceType: string;
+  url: string;
+  version?: string;
+  name: string;
+  title?: string;
+  status: string;
+  experimental?: boolean;
+  date?: string;
+  description?: string;
+  fhirVersion?: string;
+  kind: string;
+  abstract: boolean;
+  contextType?: string;
+  context?: string[];
+  contextInvariant?: string[];
+  type: string;
+  baseDefinition?: string;
+  derivation?: string;
+  snapshot?: { element: ElementDefinition[] };
+  differential?: { element: ElementDefinition[] };
+}
+
+export interface ElementDefinition {
+  id?: string;
+  path: string;
+  min?: number;
+  max?: string;
+  type?: Array<{
+    code: string;
+  }>;
+  short?: string;
+  contentReference?: string;
+}