feat(Typescript factory functions): Only first required prop is unnamed

This change attempts to balance the convienience of unnamed arguments, with the robustness of named arguments (aka keyword arguments in Python and other langs), particularly to changes in the number and order of required properties. It should mean that consumers of these factory functions do not need to change their code as often, when/if there are changes to type schemas.

ts/bindings/__file_snapshots__/Person.ts

@@ -18,13 +18,13 @@ export interface Person extends Thing {
 
 /**
  * Create a `Person` node
- * @param options Optional properties
+ * @param other Other properties
  * @returns {Person}
  */
 export const person = (
-  options: OptionalProps<Person> = {}
+  props: OptionalProps<Person> = {}
 ): Person => ({
-  ...(compact(options)),
+  ...compact(props),
   type: 'Person'
 })
 

ts/bindings/typescript.ts

@@ -135,17 +135,27 @@ export const typeGenerator = (schema: Schema): string => {
       ({ name, schema }) =>
         `@param ${name} {${schemaToType(schema)}} ${schema.description}`
     ),
-    `@param options Optional properties`,
+    `@param other Other properties`,
     `@returns {${title}}`
   ])
   code += `export const ${funcName(title)} = (\n`
-  code += required
-    .map(({ name, schema }) => `  ${name}: ${schemaToType(schema)},\n`)
-    .join('')
-  code += `  options: OptionalProps<${title}> = {}\n`
+  const firstRequired = required[0]
+  if (firstRequired !== undefined)
+    code += `  ${firstRequired.name}: ${schemaToType(firstRequired.schema)},\n`
+  const propsType =
+    (required.length > 1
+      ? '{' +
+        required
+          .slice(1)
+          .map(({ name, schema }) => `${name}: ${schemaToType(schema)}`)
+          .join('; ') +
+        '} &'
+      : '') + `OptionalProps<${title}>`
+  const propsDefault = required.length < 2 ? ' = {}' : ''
+  code += `  props: ${propsType}${propsDefault}\n`
   code += `): ${title} => ({\n`
-  code += required.map(({ name }) => `  ${name},\n`).join('')
-  code += `  ...(compact(options)),\n`
+  if (firstRequired !== undefined) code += `  ${firstRequired.name},\n`
+  code += `  ...compact(props),\n`
   code += `  type: '${title}'\n`
   code += '})\n\n'
 

ts/types.test.ts

@@ -1,22 +1,24 @@
-import { article, organization, person } from './types'
+import { person, paragraph, link } from './types'
 
 describe('Schema factory functions', () => {
-  test('it creates a valid Person node', () => {
+  test('no required properties', () => {
     expect(person()).toMatchObject({ type: 'Person' })
   })
 
-  test('it creates a valid Article node', () => {
+  test('one required property', () => {
+    expect(paragraph(['The content of the paragraph'])).toMatchObject({
+      type: 'Paragraph',
+      content: ['The content of the paragraph']
+    })
+  })
+
+  test('more than one required property', () => {
     expect(
-      article([organization({ name: 'Stencila' })], 'Testing')
+      link(['The content of the link'], { target: 'https://example.org' })
     ).toMatchObject({
-      type: 'Article',
-      title: 'Testing',
-      authors: [
-        {
-          name: 'Stencila',
-          type: 'Organization'
-        }
-      ]
+      type: 'Link',
+      content: ['The content of the link'],
+      target: 'https://example.org'
     })
   })