test: adds JsonSchema test case for "validateBody"

lib/api/test/unit/units/validateBody.test.js

@@ -277,8 +277,74 @@ describe('validateBody', () => {
         });
       });
 
-      describe.skip('application/schema+json', () => {
-        // ...
+      describe('application/schema+json', () => {
+        describe('with matching bodies', () => {
+          const res = validateBody(
+            { body: '{ "foo": "bar" }' },
+            {
+              bodySchema: {
+                required: ['foo']
+              }
+            }
+          );
+
+          it('has "JsonSchema" validator', () => {
+            assert.propertyVal(res, 'validator', 'JsonSchema');
+          });
+
+          it('has "application/json" real type', () => {
+            assert.propertyVal(res, 'realType', 'application/json');
+          });
+
+          it('has "application/schema+json" expected type', () => {
+            assert.propertyVal(res, 'expectedType', 'application/schema+json');
+          });
+
+          it('has no errors', () => {
+            assert.lengthOf(res.results, 0);
+          });
+        });
+
+        describe('with non-matching bodies', () => {
+          const res = validateBody(
+            { body: '{ "oneTwoThree": "bar" }' },
+            {
+              bodySchema: {
+                required: ['doe']
+              }
+            }
+          );
+
+          it('has "JsonSchema" validator', () => {
+            assert.propertyVal(res, 'validator', 'JsonSchema');
+          });
+
+          it('has "application/json" real type', () => {
+            assert.propertyVal(res, 'realType', 'application/json');
+          });
+
+          it('has "application/schema+json" expected type', () => {
+            assert.propertyVal(res, 'expectedType', 'application/schema+json');
+          });
+
+          describe('produces an error', () => {
+            it('exactly one error', () => {
+              assert.lengthOf(res.results, 1);
+            });
+
+            it('has "error" severity', () => {
+              assert.propertyVal(res.results[0], 'severity', 'error');
+            });
+
+            it('has explanatory message', () => {
+              assert.propertyVal(
+                res.results[0],
+                'message',
+                `At '/doe' Missing required property: doe`
+              );
+            });
+          });
+        });
       });
     });
   });