Make maxIterations and maxErrors configurable

unexpectedjs · Mar 18, 2016 · 76938ce · 76938ce
1 parent 4bd19e6
commit 76938ce
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Showing 3 changed files with 37 additions and 9 deletions.
diff --git a/documentation/assertions/function/to-be-valid-for-all.md b/documentation/assertions/function/to-be-valid-for-all.md
@@ -19,6 +19,22 @@ expect(function (text) {
 
 This will run 100 tests with random strings of length 0-200 and succeed.
 
+You can specify the max number of iterations that the test should run and the
+number of errors it should collect before stopping.
+
+The algorithm searches for the smallest error output, so the more errors you
+allow it to collect the better the output will be. 
+
+```js
+expect(function (text) {
+  expect(unescape(escape(text)), 'to equal', text);
+}, 'to be valid for all', {
+  generators: [strings],
+  maxIterations: 1000,
+  maxErrors: 30
+});
+```
+
 I found to following code for
 [Run-length encoding](https://en.wikipedia.org/wiki/Run-length_encoding) on the
 [internet](http://rosettacode.org/wiki/Run-length_encoding#JavaScript), let's see
@@ -41,13 +57,15 @@ function rleDecode(encoded) {
   return output;
 }
 
+var g = require('chance-generators')(13);
+var strings = g.string({ length: g.natural({ max: 200 }) });
 expect(function (text) {
   expect(rleDecode(rleEncode(text)), 'to equal', text);
 }, 'to be valid for all', strings);
 ```
 
 ```output
-Ran 34 iterations and found 20 errors
+Ran 86 iterations and found 20 errors
 counterexample:
 
   Generated input: ''

diff --git a/lib/unexpected-check.js b/lib/unexpected-check.js
@@ -34,10 +34,6 @@
     return {
         name: 'unexpected-check',
         installInto: function (expect) {
-            // TODO can these be configurable?
-            var maxIterations = 100;
-            var maxErrors = 20;
-
             function convertToUnexpectedError(e) {
                 if (e && e.isUnexpected) {
                     return e;
@@ -50,8 +46,10 @@
                 }
             }
 
-            expect.addAssertion('<function> to be valid for all <function+>', function (expect, subject) {
-                var generators = Array.prototype.slice.call(arguments, 2);
+            expect.addAssertion('<function> to be valid for all <object>', function (expect, subject, options) {
+                var generators = options.generators;
+                var maxIterations = options.maxIterations || 100;
+                var maxErrors = options.maxErrors || 20;
 
                 function createTask() {
                     var args = generators.map(function (g) {
@@ -125,6 +123,14 @@
                     });
                 }
             });
+
+            expect.addAssertion('<function> to be valid for all <function+>', function (expect, subject) {
+                expect.errorMode = 'bubble';
+
+                expect(subject, 'to be valid for all', {
+                    generators: Array.prototype.slice.call(arguments, 2)
+                });
+            });
         }
     };
 });
diff --git a/test/unexpected-check.spec.js b/test/unexpected-check.spec.js
@@ -41,9 +41,13 @@ describe('unexpected-check', function () {
                 expect(sorted, 'to have length', arr.length)
                     .and('first item to be less than or equal to all', arr)
                     .and('last item to be greater than or equal to all', arr);
-            }, 'to be valid for all', arrays);
+            }, 'to be valid for all', {
+                generators: [arrays],
+                maxIterations: 20,
+                maxErrors: 20
+            });
         }, 'to throw',
-               'Ran 37 iterations and found 20 errors\n' +
+               'Ran 20 iterations and found 12 errors\n' +
                'counterexample:\n' +
                '\n' +
                '  Generated input: [ -15, -20 ]\n' +