Implement KeyGenerator

Author: contractormario

src/core/format/KeyGenerator.ts

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2018 NEM
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { UInt64 } from '../../model/UInt64';
+import { sha3_256 } from 'js-sha3';
+
+export class KeyGenerator {
+    /**
+     * @returns {UInt64} Deterministic uint64 value for the given string
+     */
+    public static fromString(input: string) {
+        if (input.length === 0) {
+            throw Error(`Input must not be empty`);
+        }
+        if (input.length > 1024) {
+            throw Error(`Input exceeds 1024 characters (has ${input.length})`);
+        }
+        const format = /^[a-zA-Z0-9_]+$/gm;
+        if (input.match(format) === null) {
+            throw Error(`Input has invalid format (accepted characters: a-z, A-Z, 0-9, _)`);
+        }
+        const hex = sha3_256(input)
+        return UInt64.fromHex(hex.substr(0, 16))
+    }
+}

src/core/format/index.ts

@@ -18,4 +18,5 @@ export * from './RawAddress';
 export * from './RawArray';
 export * from './Convert';
 export * from './IdGenerator';
+export * from './KeyGenerator';
 export * from './RawUInt64';

test/core/format/KeyGenerator.spec.ts

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2019 NEM
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { expect } from 'chai';
+import { UInt64 } from '../../../src/model/UInt64';
+import { KeyGenerator } from '../../../src/core/format/KeyGenerator';
+
+describe('key generator', () => {
+    describe('generate key from string', () => {
+        it('throws if input is empty', () => {
+            expect(() => KeyGenerator.fromString('')).to.throw(Error, 'Input must not be empty');
+        })
+        it('returns UInt64', () => {
+            expect(KeyGenerator.fromString('a')).to.be.instanceOf(UInt64);
+        })
+        it('throws if input has invalid format', () => {
+            expect(() => KeyGenerator.fromString('$abc')).to.throw(Error, '');
+            expect(() => KeyGenerator.fromString('ab-c')).to.throw(Error, '');
+            expect(() => KeyGenerator.fromString('abc.')).to.throw(Error, '');
+        })
+        it('generates correct keys', () => {
+            expect(KeyGenerator.fromString('a').toHex()).to.equal('80084BF2FBA02475');
+        })
+        it('generates keys deterministically', () => {
+            expect(KeyGenerator.fromString('abc').toHex()).to.equal('3A985DA74FE225B2');
+            expect(KeyGenerator.fromString('abc').toHex()).to.equal('3A985DA74FE225B2');
+            expect(KeyGenerator.fromString('def').toHex()).to.equal('8E0D8F672252ACB0');
+            expect(KeyGenerator.fromString('def').toHex()).to.equal('8E0D8F672252ACB0');
+            expect(KeyGenerator.fromString('abc').toHex()).to.equal('3A985DA74FE225B2');
+        })
+    })
+});