diff --git a/package.json b/package.json
index 2b3106a1..859b702c 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "lint": "eslint",
     "lint:fix": "eslint --fix",
     "test:typescript": "tstyche",
-    "test:unit": "c8 node --test",
+    "test:unit": "c8 --100 --all --include=index.js --include=lib/**/*.js --exclude=lib/schema-validator.js node --test",
     "test": "npm run test:unit && npm run test:typescript"
   },
   "repository": {
diff --git a/test/code-generation-fallbacks.test.js b/test/code-generation-fallbacks.test.js
new file mode 100644
index 00000000..6dbcf703
--- /dev/null
+++ b/test/code-generation-fallbacks.test.js
@@ -0,0 +1,158 @@
+'use strict'
+
+const { test } = require('node:test')
+
+const OriginalLocation = require('../lib/location')
+
+const buildPath = require.resolve('..')
+const locationPath = require.resolve('../lib/location')
+
+function loadBuildWithLocation (Location) {
+  require.cache[locationPath].exports = Location
+  delete require.cache[buildPath]
+
+  try {
+    return require(buildPath)
+  } finally {
+    require.cache[locationPath].exports = OriginalLocation
+    delete require.cache[buildPath]
+  }
+}
+
+class LocationWithoutSchemaId {
+  constructor (schema, _schemaId, jsonPointer = '#') {
+    this.schema = schema
+    this.schemaId = ''
+    this.jsonPointer = _schemaId ? _schemaId + jsonPointer : jsonPointer
+  }
+
+  getPropertyLocation (propertyName) {
+    return new LocationWithoutSchemaId(
+      this.schema[propertyName],
+      '',
+      this.jsonPointer + '/' + propertyName
+    )
+  }
+
+  getSchemaRef () {
+    return this.schemaId + this.jsonPointer
+  }
+}
+
+class LocationWithoutJsonPointer {
+  constructor (schema, schemaId) {
+    this.schema = schema
+    this.schemaId = schemaId
+    this.jsonPointer = ''
+  }
+
+  getPropertyLocation (propertyName) {
+    return new LocationWithoutJsonPointer(this.schema[propertyName], this.schemaId)
+  }
+
+  getSchemaRef () {
+    return this.schemaId
+  }
+}
+
+class LocationWithoutSchemaRef extends OriginalLocation {
+  getSchemaRef () {}
+}
+
+test('inline object generation without schema IDs', t => {
+  t.plan(3)
+
+  const build = loadBuildWithLocation(LocationWithoutSchemaId)
+  const stringify = build({
+    type: 'object',
+    properties: {
+      value: { type: 'string' }
+    }
+  })
+  const stringifyNullable = build({ type: 'object', nullable: true })
+
+  t.assert.equal(stringify({ value: 'test' }), '{"value":"test"}')
+  t.assert.equal(stringify(null), '{}')
+  t.assert.equal(stringifyNullable(null), 'null')
+})
+
+test('inline array generation without schema IDs', t => {
+  t.plan(6)
+
+  const build = loadBuildWithLocation(LocationWithoutSchemaId)
+  const stringify = build({ type: 'array', items: { type: 'string' } }, { largeArrayMechanism: 'default' })
+  const stringifyNullable = build({ type: 'array', nullable: true })
+  const stringifyTuple = build({
+    type: 'array',
+    items: [{ $ref: 'item' }, { type: 'number' }],
+    additionalItems: true
+  }, {
+    schema: {
+      item: { type: 'string' }
+    }
+  })
+  const stringifyFixedTuple = build({
+    type: 'array',
+    items: [{ type: 'string' }],
+    additionalItems: false
+  })
+  const stringifyLargeArray = build({ type: 'array', items: { type: 'number' } }, {
+    largeArrayMechanism: 'json-stringify',
+    largeArraySize: 1
+  })
+
+  t.assert.equal(stringify(['one', 'two']), '["one","two"]')
+  t.assert.equal(stringifyNullable(null), 'null')
+  t.assert.equal(stringifyTuple(['one', 2, true]), '["one",2,true]')
+  t.assert.throws(() => stringifyFixedTuple(['one', 'two']), /Item at 1/)
+  t.assert.equal(stringifyLargeArray([1, 2]), '[1,2]')
+  t.assert.throws(() => stringify('not-an-array'), /does not match schema definition/)
+})
+
+test('code generation reference fallbacks', t => {
+  t.plan(3)
+
+  const buildWithoutPointer = loadBuildWithLocation(LocationWithoutJsonPointer)
+  const stringifyObject = buildWithoutPointer({ type: 'object' })
+  const stringifyArray = buildWithoutPointer({ type: 'array' })
+
+  const buildWithoutRef = loadBuildWithLocation(LocationWithoutSchemaRef)
+  const stringifyWithoutRef = buildWithoutRef({ type: 'object' })
+
+  t.assert.equal(stringifyObject({}), '{}')
+  t.assert.equal(stringifyArray([]), '[]')
+  t.assert.equal(stringifyWithoutRef({}), '{}')
+})
+
+test('required-property fallback tolerates unexpected property ordering', t => {
+  t.plan(2)
+
+  const originalSort = Array.prototype.sort
+  // Deliberately fault-inject unexpected ordering to exercise the defensive branch.
+  // eslint-disable-next-line no-extend-native
+  Array.prototype.sort = function (compareFn) {
+    const result = originalSort.call(this, compareFn)
+    if (this.length === 2 && this.includes('optional') && this.includes('required')) {
+      result.reverse()
+    }
+    return result
+  }
+
+  try {
+    const build = loadBuildWithLocation(OriginalLocation)
+    const stringify = build({
+      type: 'object',
+      properties: {
+        optional: { type: 'string' },
+        required: { type: 'string' }
+      },
+      required: ['required']
+    })
+
+    t.assert.equal(stringify({ optional: 'one', required: 'two' }), '{"optional":"one","required":"two"}')
+    t.assert.throws(() => stringify({ optional: 'one' }), /"required" is required/)
+  } finally {
+    // eslint-disable-next-line no-extend-native
+    Array.prototype.sort = originalSort
+  }
+})
diff --git a/test/debug-mode.test.js b/test/debug-mode.test.js
index 5000adb9..0607f7b2 100644
--- a/test/debug-mode.test.js
+++ b/test/debug-mode.test.js
@@ -128,3 +128,11 @@ test('Validator restoreFromState', t => {
   const restored = Validator.restoreFromState(state)
   t.assert.ok(restored instanceof Validator)
 })
+
+test('Validator ignores null schemas while converting nested values', t => {
+  t.plan(1)
+
+  const validator = new Validator()
+
+  t.assert.doesNotThrow(() => validator.convertSchemaToAjvFormat(null))
+})
diff --git a/test/string.test.js b/test/string.test.js
index 518513da..6c968065 100644
--- a/test/string.test.js
+++ b/test/string.test.js
@@ -4,6 +4,14 @@ const { test } = require('node:test')
 
 const build = require('..')
 
+test('serialize an empty string', (t) => {
+  t.plan(1)
+
+  const stringify = build({ type: 'string' })
+
+  t.assert.equal(stringify(''), '""')
+})
+
 test('serialize short string', (t) => {
   t.plan(2)