alsatian-test/alsatian

import "reflect-metadata";
import { TEST_CASES } from "./_metadata-keys";
import { Unused } from "../unused";
import { markPropertyAsTest } from "./mark-property-as-test";
import { deprecate } from "../maintenance/deprecate";

function GetTestCases(
    caseArguments:
        | (() => IterableIterator<any> | Array<Array<any>>)
        | IterableIterator<any>
        | Array<Array<any>>
): Array<Array<any>> {
    if (null === caseArguments || undefined === caseArguments) {
        return [];
    }

    if (caseArguments instanceof Function) {
        return GetTestCases(caseArguments());
    }

    if (caseArguments instanceof Array) {
        return [...caseArguments];
    } else {
        return Array.from(caseArguments);
    }
}

export function TestCases(
    caseArguments:
        | (() => IterableIterator<any> | Array<Array<any>>)
        | IterableIterator<any>
        | Array<Array<any>>
): (
    target: object,
    propertyKey: string,
    descriptor?: TypedPropertyDescriptor<any>
) => void {
    deprecate("TestCases", "5.0.0", "Please switch to using the new TestProperties decorator.");

    return (
        target: object,
        propertyKey: string,
        descriptor?: TypedPropertyDescriptor<any>
    ) => {
        Unused(descriptor);

        markPropertyAsTest(propertyKey, target);

        const testCases = GetTestCases(caseArguments).reduce((acc, val) => {
            // add the test case to the list
            return [
                ...acc,
                {
                    caseArguments: val
                }
            ];
        }, (Reflect.getMetadata(TEST_CASES, target, propertyKey) as Array<any>) || []);

        // update the list of test cases
        Reflect.defineMetadata(TEST_CASES, testCases, target, propertyKey);
    };
}