feat(markdown): add support for default keyword

lib/markdownBuilder.js

@@ -642,6 +642,17 @@ function build({
     return [];
   }
 
+  function makedefault(schema, level = 1) {
+    if (schema[keyword`default`]) {
+      return [
+        heading(level + 1, text(i18n`${simpletitle(schema)} Default Value`)),
+        paragraph(text(i18n`The default value is:`)),
+        paragraph(code('json', JSON.stringify(schema[keyword`default`], undefined, 2))),
+      ];
+    }
+    return [];
+  }
+
   function makeproplist(properties = {},
     patternProperties = {},
     additionalProperties,
@@ -658,6 +669,7 @@ function build({
           makefactlist(name, definition, required),
           ...maketypesection(definition, level + 1),
           ...makeconstraintssection(definition, level + 1),
+          ...makedefault(definition, level + 1),
           ...makeexamples(definition, level + 1),
         ];
       }))),
@@ -671,6 +683,7 @@ function build({
           makefactlist(name, definition, required),
           ...maketypesection(definition, level + 1),
           ...makeconstraintssection(definition, level + 1),
+          ...makedefault(definition, level + 1),
           ...makeexamples(definition, level + 1),
         ];
       }))),
@@ -684,6 +697,7 @@ function build({
             makefactlist(i18n`Additional properties`, definition, required),
             ...maketypesection(definition, level + 1),
             ...makeconstraintssection(definition, level + 1),
+            ...makedefault(definition, level + 1),
             ...makeexamples(definition, level + 1),
           ];
         } else if (additionalProperties === true) {
@@ -771,6 +785,7 @@ function build({
       ...makeheader(schema),
       ...maketypesection(schema, 1),
       ...makeconstraintssection(schema, 1),
+      ...makedefault(schema, 1),
       ...makeexamples(schema, 1),
       ...makedefinitions(schema, slugger),
       ...makeproperties(schema, slugger),

schemasupport.md

@@ -1,6 +1,6 @@
 # JSON Schema Spec Coverage Report
 
-This report lists the keywords of the JSON Schema spec that are covered in the tests. The overall coverage is 73%
+This report lists the keywords of the JSON Schema spec that are covered in the tests. The overall coverage is 74%
 
 ## The JSON Schema Core Vocabulary
 
@@ -135,11 +135,11 @@ Coverage for [A Vocabulary for the Contents of String-Encoded Data](https://json
 
 ## A Vocabulary for Basic Meta-Data Annotations
 
-Coverage for [A Vocabulary for Basic Meta-Data Annotations](https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9) is 42%.
+Coverage for [A Vocabulary for Basic Meta-Data Annotations](https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9) is 57%.
 
 | Keyword       | Supported |
 | :------------ | --------- |
-| `default`     | No        |
+| `default`     | Yes       |
 | `deprecated`  | No        |
 | `description` | Yes       |
 | `examples`    | Yes       |

test/fixtures/readme-1/simple.schema.json

@@ -17,6 +17,10 @@
           "description": "A unique identifier given to every addressable thing.",
           "version": "1.0.0",
           "testProperty": "test"
+      },
+      "name": {
+          "type": "string",
+          "default": "Simply Untitled"
       }
   }
 }

test/markdownBuilder.test.js

@@ -279,6 +279,7 @@ Reference this group by using
 
   it('Simple Schema looks OK', () => {
     assertMarkdown(results.simple)
+      .contains('"Simply Untitled"')
       .contains('# Simple Schema');
   });
 });

test/zSchemaCoverage.test.js

@@ -25,6 +25,7 @@ const expected = [
   'relative-json-pointer',
   'regex',
   'uri-template',
+  'default',
 ];
 
 const allkeywords = {