feat(content): LiteralMap, LiteralValue

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>

src/content/__tests__/literal.spec-d.ts

@@ -0,0 +1,28 @@
+/**
+ * @file Type Tests - literal
+ * @module esast/content/tests/unit-d/literal
+ */
+
+import type { PrimitiveMap, RegExpLiteral } from '@flex-development/esast'
+import type * as TestSubject from '../literal'
+
+describe('unit-d:content/literal', () => {
+  describe('LiteralMap', () => {
+    it('should extend PrimitiveMap', () => {
+      expectTypeOf<TestSubject.LiteralMap>().toMatchTypeOf<PrimitiveMap>()
+    })
+
+    it('should match [regexp: RegExpLiteral]', () => {
+      expectTypeOf<TestSubject.LiteralMap>()
+        .toHaveProperty('regexp')
+        .toEqualTypeOf<RegExpLiteral>
+    })
+  })
+
+  describe('LiteralValue', () => {
+    it('should equal LiteralMap[keyof LiteralMap]', () => {
+      expectTypeOf<TestSubject.LiteralValue>()
+        .toEqualTypeOf<TestSubject.LiteralMap[keyof TestSubject.LiteralMap]>
+    })
+  })
+})

src/content/index.ts

@@ -3,4 +3,5 @@
  * @module esast/content
  */
 
+export type * from './literal'
 export type * from './primitive'

src/content/literal.ts

@@ -0,0 +1,36 @@
+/**
+ * @file Content - literal
+ * @module esast/content/literal
+ */
+
+import type { PrimitiveMap, RegExpLiteral } from '@flex-development/esast'
+
+/**
+ * Union of registered esast nodes that can occur where a literal value is
+ * expected.
+ *
+ * To register custom esast nodes, augment {@linkcode LiteralMap}. They will be
+ * added to this union automatically.
+ */
+type LiteralValue = LiteralMap[keyof LiteralMap]
+
+/**
+ * Registry of nodes that can occur where a {@linkcode LiteralValue} is
+ * expected.
+ *
+ * This interface can be augmented to register custom node types.
+ *
+ * @example
+ *  declare module '@flex-development/docast' {
+ *    interface LiteralMap {
+ *      custom: CustomLiteral
+ *    }
+ *  }
+ *
+ * @extends {PrimitiveMap}
+ */
+interface LiteralMap extends PrimitiveMap {
+  regexp: RegExpLiteral
+}
+
+export type { LiteralMap, LiteralValue }