move logger, pseudorandom, wrapper_interfaces to framework/utils/

contracts/integrations/test/framework/utils/pseudorandom.ts

@@ -0,0 +1,39 @@
+import { Numberish } from '@0x/contracts-test-utils';
+import { BigNumber } from '@0x/utils';
+import * as seedrandom from 'seedrandom';
+
+class PRNGWrapper {
+    public readonly seed = process.env.UUID || Math.random().toString();
+    private readonly _rng = seedrandom(this.seed);
+
+    /*
+     * Pseudorandom version of _.sample. Picks an element of the given array with uniform probability.
+     * Return undefined if the array is empty.
+     */
+    public sample<T>(arr: T[]): T | undefined {
+        if (arr.length === 0) {
+            return undefined;
+        }
+        const index = Math.abs(this._rng.int32()) % arr.length;
+        return arr[index];
+    }
+
+    // tslint:disable:unified-signatures
+    /*
+     * Pseudorandom version of getRandomPortion/getRandomInteger. If two arguments are provided,
+     * treats those arguments as the min and max (inclusive) of the desired range. If only one
+     * argument is provided, picks an integer between 0 and the argument.
+     */
+    public integer(max: Numberish): BigNumber;
+    public integer(min: Numberish, max: Numberish): BigNumber;
+    public integer(a: Numberish, b?: Numberish): BigNumber {
+        if (b === undefined) {
+            return new BigNumber(this._rng()).times(a).integerValue(BigNumber.ROUND_HALF_UP);
+        } else {
+            const range = new BigNumber(b).minus(a);
+            return this.integer(range).plus(a);
+        }
+    }
+}
+
+export const Pseudorandom = new PRNGWrapper();