feat(Util): Add version and URL utility functions

ts/bindings/jsonld.ts

@@ -11,23 +11,9 @@ import fs from 'fs-extra'
 import fromEntries from 'object.fromentries'
 import path from 'path'
 import { readSchemas } from '../helpers'
+import { jsonLdUrl } from '../util'
 
-/**
- * Get the Schema major version for use in generated URLs
- */
-const VERSION_MAJOR = fs
-  .readJSONSync(path.join(__dirname, '..', '..', 'package.json'))
-  .version.split('.')[0]
-
-/**
- * The base URL for the Stencila JSON-LD context.
- *
- * This gets prefixed to all keys during JSON-LD expansion
- * so the trailing slash is important so that for e.g.
- * `CodeChunk` gets expanded to `http://schema.stenci.la/v0/jsonld/CodeChunk`
- * (which in gets redirected to `https://unpkg.com/@stencila/schema@0.32.1/dist/CodeChunk.jsonld`)
- */
-const STENCILA_CONTEXT_URL = `http://schema.stenci.la/v${VERSION_MAJOR}/jsonld/`
+const STENCILA_CONTEXT_URL = jsonLdUrl()
 
 /**
  * The destination directory for generated JSON-LD files

ts/schema.ts

@@ -13,22 +13,16 @@ import cloneDeep from 'lodash.clonedeep'
 import path from 'path'
 import log from './log'
 import Schema from './schema-interface'
+import { versionMajor } from './util/version'
 
 const SCHEMA_SOURCE_DIR = path.join(__dirname, '..', 'schema')
 const SCHEMA_DEST_DIR = path.join(__dirname, '..', 'public')
 
-/**
- * Get the Schema major version for use in generated URLs
- */
-const VERSION_MAJOR = fs
-  .readJSONSync(path.join(__dirname, '..', 'package.json'))
-  .version.split('.')[0]
-
 /**
  * The base URL for JSON Schema `$id`s.
  */
 const SCHEMA_DEST_URL = 'https://schema.stenci.la'
-const ID_BASE_URL = `${SCHEMA_DEST_URL}/v${VERSION_MAJOR}`
+const ID_BASE_URL = `${SCHEMA_DEST_URL}/v${versionMajor()}`
 
 /**
  * The base URL for source files.

ts/util/index.ts

@@ -2,3 +2,5 @@ export * from './guards'
 export * from './node-type'
 export * from './type-map'
 export * from './type-maps'
+export * from './urls'
+export * from './version'

ts/util/urls.test.ts

@@ -0,0 +1,11 @@
+import pkg from '../../package.json'
+import { jsonLdUrl } from './urls'
+
+test('jsonLdUrl', () => {
+  const expectedBase = `http://schema.stenci.la/v${
+    pkg.version.split('.')[0]
+  }/jsonld/`
+  expect(jsonLdUrl()).toMatch(expectedBase)
+  expect(jsonLdUrl('CodeChunk')).toMatch(expectedBase + 'CodeChunk')
+  expect(jsonLdUrl('outputs')).toMatch(expectedBase + 'outputs')
+})

ts/util/urls.ts

@@ -0,0 +1,18 @@
+import { versionMajor } from './version'
+
+/**
+ * Get the URL to the JSON-LD for this schema's `@context` or
+ * for a specific term e.g. `CodeChunk`, `outputs`.
+ *
+ * The `@context`'s URL needs to have a trailing slash because
+ * it gets prefixed to all keys during JSON-LD expansion.
+ * e.g. the term `CodeChunk` gets expanded to `http://schema.stenci.la/v0/jsonld/CodeChunk`
+ * (which in gets redirected to `https://unpkg.com/@stencila/schema@0.32.1/dist/CodeChunk.jsonld`)
+ *
+ * @param term The term (type or property) to generate the
+ *             URL for. Defaults to empty string i.e. the context.
+ */
+export function jsonLdUrl(term = '') {
+  const version = versionMajor()
+  return `http://schema.stenci.la/v${version}/jsonld/${term}`
+}

ts/util/version.test.ts

@@ -0,0 +1,19 @@
+import pkg from '../../package.json'
+import { version, versionMajor, versionMinor } from './version'
+
+test('version', () => {
+  expect(version()).toEqual(pkg.version)
+})
+
+test('versionMajor', () => {
+  expect(versionMajor()).toEqual(pkg.version.split('.')[0])
+})
+
+test('versionMinor', () => {
+  expect(versionMinor()).toEqual(
+    pkg.version
+      .split('.')
+      .slice(0, 2)
+      .join('.')
+  )
+})

ts/util/version.ts

@@ -0,0 +1,39 @@
+import fs from 'fs'
+import path from 'path'
+
+/**
+ * Lazily read, cached, package version
+ */
+let VERSION: string
+
+/**
+ * Get the version string (e.g "1.2.3") for this package
+ */
+export function version(): string {
+  if (VERSION === undefined) {
+    const json = fs.readFileSync(
+      path.join(__dirname, '..', '..', 'package.json'),
+      'utf8'
+    )
+    const pkg = JSON.parse(json)
+    VERSION = pkg.version
+  }
+  return VERSION
+}
+
+/**
+ * Get the major version string (e.g "1") for this package
+ */
+export function versionMajor(): string {
+  return version().split('.')[0]
+}
+
+/**
+ * Get the minor version string (e.g "1.2") for this package
+ */
+export function versionMinor(): string {
+  return version()
+    .split('.')
+    .slice(0, 2)
+    .join('.')
+}