import * as chai from 'chai';
import * as _ from 'lodash';
import { chaiSetup } from './chai_setup';
chaiSetup.configure();
const expect = chai.expect;
export async function testWithReferenceFuncAsync<P0, R>(
referenceFunc: (p0: P0) => Promise<R>,
testFunc: (p0: P0) => Promise<R>,
values: [P0],
): Promise<void>;
export async function testWithReferenceFuncAsync<P0, P1, R>(
referenceFunc: (p0: P0, p1: P1) => Promise<R>,
testFunc: (p0: P0, p1: P1) => Promise<R>,
values: [P0, P1],
): Promise<void>;
export async function testWithReferenceFuncAsync<P0, P1, P2, R>(
referenceFunc: (p0: P0, p1: P1, p2: P2) => Promise<R>,
testFunc: (p0: P0, p1: P1, p2: P2) => Promise<R>,
values: [P0, P1, P2],
): Promise<void>;
export async function testWithReferenceFuncAsync<P0, P1, P2, P3, R>(
referenceFunc: (p0: P0, p1: P1, p2: P2, p3: P3) => Promise<R>,
testFunc: (p0: P0, p1: P1, p2: P2, p3: P3) => Promise<R>,
values: [P0, P1, P2, P3],
): Promise<void>;
export async function testWithReferenceFuncAsync<P0, P1, P2, P3, P4, R>(
referenceFunc: (p0: P0, p1: P1, p2: P2, p3: P3, p4: P4) => Promise<R>,
testFunc: (p0: P0, p1: P1, p2: P2, p3: P3, p4: P4) => Promise<R>,
values: [P0, P1, P2, P3, P4],
): Promise<void>;
/**
* Tests the behavior of a test function by comparing it to the expected
* behavior (defined by a reference function).
*
* First the reference function will be called to obtain an "expected result",
* or if the reference function throws/rejects, an "expected error". Next, the
* test function will be called to obtain an "actual result", or if the test
* function throws/rejects, an "actual error". The test passes if at least one
* of the following conditions is met:
*
* 1) Neither the reference function or the test function throw and the
* "expected result" equals the "actual result".
*
* 2) Both the reference function and the test function throw and the "actual
* error" message *contains* the "expected error" message.
*
* @param referenceFuncAsync a reference function implemented in pure
* JavaScript/TypeScript which accepts N arguments and returns the "expected
* result" or throws/rejects with the "expected error".
* @param testFuncAsync a test function which, e.g., makes a call or sends a
* transaction to a contract. It accepts the same N arguments returns the
* "actual result" or throws/rejects with the "actual error".
* @param values an array of N values, where each value corresponds in-order to
* an argument to both the test function and the reference function.
* @return A Promise that resolves if the test passes and rejects if the test
* fails, according to the rules described above.
*/
export async function testWithReferenceFuncAsync(
referenceFuncAsync: (...args: any[]) => Promise<any>,
testFuncAsync: (...args: any[]) => Promise<any>,
values: any[],
): Promise<void> {
let expectedResult: any;
let expectedErr: string | undefined;
try {
expectedResult = await referenceFuncAsync(...values);
} catch (e) {
expectedErr = e.message;
}
let actualResult: any | undefined;
try {
actualResult = await testFuncAsync(...values);
if (!_.isUndefined(expectedErr)) {
throw new Error(
`Expected error containing ${expectedErr} but got no error\n\tTest case: ${_getTestCaseString(
referenceFuncAsync,
values,
)}`,
);
}
} catch (e) {
if (_.isUndefined(expectedErr)) {
throw new Error(`${e.message}\n\tTest case: ${_getTestCaseString(referenceFuncAsync, values)}`);
} else {
expect(e.message).to.contain(
expectedErr,
`${e.message}\n\tTest case: ${_getTestCaseString(referenceFuncAsync, values)}`,
);
}
}
if (!_.isUndefined(actualResult) && !_.isUndefined(expectedResult)) {
expect(actualResult).to.deep.equal(
expectedResult,
`Test case: ${_getTestCaseString(referenceFuncAsync, values)}`,
);
}
}
function _getTestCaseString(referenceFuncAsync: (...args: any[]) => Promise<any>, values: any[]): string {
const paramNames = _getParameterNames(referenceFuncAsync);
return JSON.stringify(_.zipObject(paramNames, values));
}
// Source: https://stackoverflow.com/questions/1007981/how-to-get-function-parameter-names-values-dynamically
function _getParameterNames(func: (...args: any[]) => any): string[] {
return _.toString(func)
.replace(/[/][/].*$/gm, '') // strip single-line comments
.replace(/\s+/g, '') // strip white space
.replace(/[/][*][^/*]*[*][/]/g, '') // strip multi-line comments
.split('){', 1)[0]
.replace(/^[^(]*[(]/, '') // extract the parameters
.replace(/=[^,]+/g, '') // strip any ES6 defaults
.split(',')
.filter(Boolean); // split & filter [""]
}
