fix: #473 make concat compatible with (not)oneOf (#492)

* fix: #473 make concat compatible with (not)oneOf

* Combine RefSet.union() and setminus() into single merge() function

src/mixed.js

@@ -24,9 +24,7 @@ class RefSet {
     Ref.isRef(value) ? this.refs.set(value.key, value) : this.list.add(value);
   }
   delete(value) {
-    Ref.isRef(value)
-      ? this.refs.delete(value.key, value)
-      : this.list.delete(value);
+    Ref.isRef(value) ? this.refs.delete(value.key) : this.list.delete(value);
   }
   has(value, resolve) {
     if (this.list.has(value)) return true;
@@ -38,6 +36,20 @@ class RefSet {
 
     return false;
   }
+  clone() {
+    const next = new RefSet();
+    next.list = new Set(this.list);
+    next.refs = new Map(this.refs);
+    return next;
+  }
+  merge(newItems, removeItems) {
+    const next = this.clone();
+    newItems.list.forEach(value => next.add(value));
+    newItems.refs.forEach(value => next.add(value));
+    removeItems.list.forEach(value => next.delete(value));
+    removeItems.refs.forEach(value => next.delete(value));
+    return next;
+  }
 }
 
 export default function SchemaType(options = {}) {
@@ -112,12 +124,23 @@ const proto = (SchemaType.prototype = {
 
     var next = prependDeep(schema.clone(), this);
 
-    // new undefined default is overriden by old non-undefined one, revert
+    // new undefined default is overridden by old non-undefined one, revert
     if (has(schema, '_default')) next._default = schema._default;
 
     next.tests = this.tests;
     next._exclusive = this._exclusive;
 
+    // manually merge the blacklist/whitelist (the other `schema` takes
+    // precedence in case of conflicts)
+    next._whitelist = this._whitelist.merge(
+      schema._whitelist,
+      schema._blacklist,
+    );
+    next._blacklist = this._blacklist.merge(
+      schema._blacklist,
+      schema._whitelist,
+    );
+
     // manually add the new tests to ensure
     // the deduping logic is consistent
     next.withMutation(next => {

test/mixed.js

@@ -670,6 +670,47 @@ describe('Mixed Types ', () => {
     );
   });
 
+  it('concat should preserve oneOf', async function() {
+    let inst = string()
+      .oneOf(['a'])
+      .concat(string().default('hi'));
+
+    await inst.isValid('a').should.become(true);
+  });
+
+  it('gives whitelist precedence to second in concat', async function() {
+    let inst = string()
+      .oneOf(['a', 'b', 'c'])
+      .concat(string().notOneOf(['b']));
+
+    await inst.isValid('a').should.become(true);
+    await inst.isValid('b').should.become(false);
+    await inst.isValid('c').should.become(true);
+  });
+
+  it('gives blacklist precedence to second in concat', async function() {
+    let inst = string()
+      .notOneOf(['a', 'b', 'c'])
+      .concat(string().oneOf(['b', 'c']));
+
+    await inst.isValid('a').should.become(false);
+    await inst.isValid('b').should.become(true);
+    await inst.isValid('c').should.become(true);
+  });
+
+  it('concats whitelist with refs', async function() {
+    let inst = object({
+      x: string().required(),
+      y: string()
+        .oneOf([ref('$x'), 'b', 'c'])
+        .concat(string().notOneOf(['c', ref('$x')])),
+    });
+
+    await inst.isValid({ x: 'a', y: 'a' }).should.become(false);
+    await inst.isValid({ x: 'a', y: 'b' }).should.become(true);
+    await inst.isValid({ x: 'a', y: 'c' }).should.become(false);
+  });
+
   it('defaults should be validated but not transformed', function() {
     let inst = string()
       .trim()