Improve test coverage

simple-statistics · May 23, 2015 · cc7ae88 · cc7ae88
1 parent ae58d1e
commit cc7ae88
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Showing 4 changed files with 23 additions and 5 deletions.
diff --git a/src/simple_statistics.js b/src/simple_statistics.js
@@ -8,13 +8,16 @@
 (function() {
     var ss = {};
 
+    /* istanbul ignore else */
     if (typeof module !== 'undefined') {
         // Assign the `ss` object to exports, so that you can require
         // it in [node.js](http://nodejs.org/)
         module.exports = ss;
     } else {
         // Otherwise, in a browser, we assign `ss` to the window object,
         // so you can simply refer to it as `ss`.
+        // Coverage testing will always skip this line, so we exclude
+        // it from istanbul's vision.
         this.ss = ss;
     }
 
@@ -1453,6 +1456,8 @@
     // of Javascript.
     function mixin(array) {
         var support = !!(Object.defineProperty && Object.defineProperties);
+        // Coverage testing will never test this error.
+        /* istanbul ignore next */
         if (!support) throw new Error('without defineProperty, simple-statistics cannot be mixed in');
 
         // only methods which work on basic arrays in a single step

diff --git a/test/chi_squared_goodness_of_fit.test.js b/test/chi_squared_goodness_of_fit.test.js
@@ -19,5 +19,9 @@ test('chi_squared_goodness_of_fit', function(t) {
         t.equal(true, ss.chi_squared_goodness_of_fit(data_10_19, ss.poisson_distribution, 0.10));
         t.end();
     });
+    test('can tolerate gaps in distribution', function(t) {
+        t.equal(true, ss.chi_squared_goodness_of_fit([0, 2, 3, 7, 7, 7, 7, 7, 7, 9, 10], ss.poisson_distribution, 0.10));
+        t.end();
+    });
     t.end();
 });
diff --git a/test/cumulative.js b/test/cumulative.js
@@ -4,20 +4,22 @@ var ss = require('../');
 test('cumulative_std_normal_probability', function(t) {
     // https://en.wikipedia.org/wiki/Standard_normal_table#Examples_of_use
     test('wikipedia test example works', function(t) {
-        for (var i = 0; i < ss.standard_normal_table.length; i++) {
-            t.equal(ss.cumulative_std_normal_probability(0.4), 0.6554);
-        }
+        t.equal(ss.cumulative_std_normal_probability(0.4), 0.6554);
         t.end();
     });
     test('nondecreasing', function(t) {
         for (var i = 0; i < ss.standard_normal_table.length; i++) {
-            t.equal(ss.cumulative_std_normal_probability(i / 100) >= ss.cumulative_std_normal_probability((i - 1) / 100), true);
+            if (!ss.cumulative_std_normal_probability(i / 100) >= ss.cumulative_std_normal_probability((i - 1) / 100)) {
+                t.fail('non-decreasing failure on ' + i);
+            }
         }
         t.end();
     });
     test('matches error_function', function(t) {
         for (var i = 0; i < ss.standard_normal_table.length; i++) {
-            t.equal(Math.abs(ss.cumulative_std_normal_probability(i / 100) - (.5 + .5 * ss.error_function(i / 100 / Math.sqrt(2)))) < ss.epsilon, true);
+            if (!(Math.abs(ss.cumulative_std_normal_probability(i / 100) - (.5 + .5 * ss.error_function(i / 100 / Math.sqrt(2)))) < ss.epsilon)) {
+                t.fail('error-fn failure on ' + i);
+            }
         }
         t.end();
     });

diff --git a/test/shuffle.test.js b/test/shuffle.test.js
@@ -22,3 +22,10 @@ test('shuffle_in_place', function(t) {
     t.deepEqual(input, [6, 1, 5, 2, 4, 3], 'changes original array');
     t.end();
 });
+
+test('shuffle_in_place truly random', function(t) {
+    var input = [1, 2, 3, 4, 5, 6];
+    t.deepEqual(ss.shuffle_in_place([]), []);
+    t.deepEqual(ss.shuffle_in_place(input).sort(), [1, 2, 3, 4, 5, 6]);
+    t.end();
+});