Fix: Registry Support for Case Insensitive Functions (elastic#807)

* Change registry get function to case insenstive comparison

* Change registry to register lower version of function names

* Added check for undefined name in registry get function

* Throws when prop isn't a string in registry constructor

* Added unit tests for registry

common/lib/__tests__/registry.js

@@ -6,6 +6,11 @@ function validateRegistry(registry, elements) {
     expect(registry.get('__test2')).to.eql(elements[1]());
   });
 
+  it('ignores case when getting items', () => {
+    expect(registry.get('__TeSt2')).to.eql(elements[1]());
+    expect(registry.get('__tESt2')).to.eql(elements[1]());
+  });
+
   it('gets a shallow clone', () => {
     expect(registry.get('__test2')).to.not.equal(elements[1]());
   });
@@ -169,4 +174,11 @@ describe('Registry', () => {
       expect(val[name].baseFunc).to.be.a('function');
     });
   });
+
+  describe('throws when lookup prop is not a string', () => {
+    const check = () => new Registry(2);
+    expect(check).to.throwException(e => {
+      expect(e.message).to.be('Registry property name must be a string');
+    });
+  });
 });

common/lib/registry.js

@@ -2,6 +2,7 @@ import clone from 'lodash.clone';
 
 export class Registry {
   constructor(prop = 'name') {
+    if (typeof prop !== 'string') throw new Error('Registry property name must be a string');
     this._prop = prop;
     this._indexed = new Object();
   }
@@ -19,7 +20,7 @@ export class Registry {
     if (typeof obj !== 'object' || !obj[this._prop]) {
       throw new Error(`Registered functions must return an object with a ${this._prop} property`);
     }
-    this._indexed[obj[this._prop]] = this.wrapper(obj);
+    this._indexed[obj[this._prop].toLowerCase()] = this.wrapper(obj);
   }
 
   toJS() {
@@ -34,7 +35,9 @@ export class Registry {
   }
 
   get(name) {
-    return this._indexed[name] ? clone(this._indexed[name]) : null;
+    if (name === undefined) return null;
+    const lowerCaseName = name.toLowerCase();
+    return this._indexed[lowerCaseName] ? clone(this._indexed[lowerCaseName]) : null;
   }
 
   getProp() {