assertArrayAlmostEqual -> getAlmostEqualElemsCount; add assertArrayAlmostEqual

OlegStotsky · JasonShin · commit 9e2fa6edc351 · 2019-08-20T22:18:27.000+10:00
diff --git a/src/lib/utils/Errors.ts b/src/lib/utils/Errors.ts
@@ -1,5 +1,15 @@
 // NOTE: Below custom errors are hack because Jest has a bug with asserting error types
 
+/**
+ * The error is used to indicate that some assertion failed
+ * @ignore
+ */
+export const AssertionError = function(message) {
+  Error.captureStackTrace(this, this.constructor);
+  this.name = this.constructor.name;
+  this.message = message;
+};
+
 /**
  * The error is used for class initiation failures due to invalid arguments.
  * @ignore
diff --git a/test/util_testing.ts b/test/util_testing.ts
@@ -1,21 +1,38 @@
-import * as _ from 'lodash';
+import { AssertionError } from '../src/lib/utils/Errors';
 
 /**
- * Raises an AssertionError if two objects are not equal up to desired precision.
+ * Raises an AssertionError if two arrays are not equal up to desired precision.
  * @param desired
  * @param actual
  * @param precision
  */
-const assertArrayAlmostEqual = (desired: number[], actual: number[], precision: number = 6): number => {
+const getAlmostEqualElemsCount = (desired: number[], actual: number[], precision: number = 6): number => {
   const results = [];
   for (let i = 0; i < desired.length; i++) {
     const d = desired[i];
     const a = actual[i];
-    const calc = Math.abs(d - a) < 1.5 * Math.pow(10, -precision);
-    results.push(calc);
+    if (Number.isNaN(a) && Number.isNaN(d)) {
+      results.push(true);
+    } else {
+      const calc = Math.abs(d - a) < 1.5 * Math.pow(10, -precision);
+      results.push(calc);
+    }
   }
   const numTrues = results.reduce((sum, cur) => (cur ? sum + 1 : sum), 0);
-  return numTrues / results.length * 100;
+
+  return numTrues;
+};
+
+const assertArrayAlmostEqual = (desired: number[], actual: number[], precision: number = 6) => {
+  if (desired.length !== actual.length) {
+    throw new AssertionError('Desired and actual arrays should have the same length');
+  }
+
+  const numAlmostEqualElems = getAlmostEqualElemsCount(desired, actual, precision);
+
+  if (numAlmostEqualElems < desired.length) {
+    throw new AssertionError(`Expected ${desired.length} almost equal numbers, got ${numAlmostEqualElems}`);
+  }
 };
 
 const matchExceptionWithSnapshot = (method: (...x) => any, args: any[]): void => {
@@ -26,4 +43,4 @@ const matchExceptionWithSnapshot = (method: (...x) => any, args: any[]): void =>
   }
 };
 
-export { assertArrayAlmostEqual, matchExceptionWithSnapshot };
+export { assertArrayAlmostEqual, getAlmostEqualElemsCount, matchExceptionWithSnapshot };
