js sdk: expose type.describe() for convenience (#1667)

js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@attic/noms",
-  "version": "41.3.0",
+  "version": "41.4.0",
   "description": "Noms JS SDK",
   "repository": "https://github.com/attic-labs/noms",
   "main": "dist/commonjs/noms.js",

js/src/type-test.js

@@ -121,4 +121,16 @@ suite('Type', () => {
     assertValid('a_');
     assertValid('a0_');
   });
+
+  test('type.describe', () => {
+    // This is tested exaustively as part of HRS, just testing here that
+    // type.describe() is present and works.
+    [
+      [numberType, 'Number'],
+      [stringType, 'String'],
+      [makeSetType(numberType), 'Set<Number>'],
+    ].forEach(([t, desc]) => {
+      assert.equal(t.describe(), desc);
+    });
+  });
 });

js/src/type.js

@@ -8,6 +8,7 @@ import {isPrimitiveKind, Kind} from './noms-kind.js';
 import {ValueBase} from './value.js';
 import type Value from './value.js';
 import {compare, equals} from './compare.js';
+import {describeType} from './encode-human-readable.js';
 
 export interface TypeDesc {
   kind: NomsKind;
@@ -142,6 +143,10 @@ export class Type<T: TypeDesc> extends ValueBase {
     invariant(this._desc instanceof CompoundDesc);
     return this._desc.elemTypes;
   }
+
+  describe(): string {
+    return describeType(this);
+  }
 }
 
 function buildType<T: TypeDesc>(desc: T): Type<T> {