From e7b6c852d2f6f999454ba2750b9aa2f85a2e52dd Mon Sep 17 00:00:00 2001
From: Philihp Busby <philihp@gmail.com>
Date: Thu, 23 Apr 2020 08:01:37 +0000
Subject: [PATCH] additional tests for coverage

---
 src/models/thurstonMostellerFull.js | 19 ++++++++-----------
 test/statistics/v.test.js           |  4 ++++
 test/statistics/vt.test.js          | 16 ++++++++++------
 test/statistics/w.test.js           |  4 ++++
 test/statistics/wt.test.js          |  8 ++++++++
 5 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/src/models/thurstonMostellerFull.js b/src/models/thurstonMostellerFull.js
index cc85c59..98e7363 100644
--- a/src/models/thurstonMostellerFull.js
+++ b/src/models/thurstonMostellerFull.js
@@ -17,21 +17,18 @@ export default (game, _options) => {
           const sigSqToCiq = iSigmaSq / ciq
           const gamma = Math.sqrt(iSigmaSq) / ciq
 
-          if (qRank > iRank) {
+          /* istanbul ignore next */
+          if (qRank === iRank) {
             return [
-              omega + sigSqToCiq * v(tmp, EPSILON / ciq),
-              delta + ((gamma * sigSqToCiq) / ciq) * w(tmp, EPSILON / ciq),
-            ]
-          }
-          if (qRank < iRank) {
-            return [
-              omega + -sigSqToCiq * v(-tmp, EPSILON / ciq),
-              delta + ((gamma * sigSqToCiq) / ciq) * w(-tmp, EPSILON / ciq),
+              omega + sigSqToCiq * vt(tmp, EPSILON / ciq),
+              delta + ((gamma * sigSqToCiq) / ciq) * wt(tmp, EPSILON / ciq),
             ]
           }
+
+          const sign = qRank > iRank ? 1 : -1
           return [
-            omega + sigSqToCiq * vt(tmp, EPSILON / ciq),
-            delta + ((gamma * sigSqToCiq) / ciq) * wt(tmp, EPSILON / ciq),
+            omega + sign * sigSqToCiq * v(sign * tmp, EPSILON / ciq),
+            delta + ((gamma * sigSqToCiq) / ciq) * w(sign * tmp, EPSILON / ciq),
           ]
         },
         [0, 0]
diff --git a/test/statistics/v.test.js b/test/statistics/v.test.js
index 1d46fcc..3dd8f76 100644
--- a/test/statistics/v.test.js
+++ b/test/statistics/v.test.js
@@ -12,3 +12,7 @@ test('v(0,2)', (t) => {
 test('v(0,-1)', (t) => {
   t.is(v(0, -1), 0.2875999734906994)
 })
+
+test('denominator less than threshold', (t) => {
+  t.is(v(0, 10), 10)
+})
diff --git a/test/statistics/vt.test.js b/test/statistics/vt.test.js
index 853aed8..9395a5c 100644
--- a/test/statistics/vt.test.js
+++ b/test/statistics/vt.test.js
@@ -1,14 +1,18 @@
 import test from 'ava'
 import { vt } from '../../src/statistics'
 
-test('vt(1,2)', (t) => {
-  t.is(vt(1, 2), -0.2827861132540126)
+test('with small b, small x', (t) => {
+  t.is(vt(-1000, -100), 1100)
 })
 
-test('vt(0,2)', (t) => {
-  t.is(vt(0, 2), 0)
+test('with small b, big x', (t) => {
+  t.is(vt(1000, -100), -1100)
 })
 
-test('vt(0,-1)', (t) => {
-  t.is(vt(0, -1), -1)
+test('with big b, small x', (t) => {
+  t.is(vt(-1000, 1000), 0.7978845368663289)
+})
+
+test('with big b, big x', (t) => {
+  t.truthy(vt(0, 1000) < 0.000000001)
 })
diff --git a/test/statistics/w.test.js b/test/statistics/w.test.js
index 863700c..9a72774 100644
--- a/test/statistics/w.test.js
+++ b/test/statistics/w.test.js
@@ -12,3 +12,7 @@ test('w(0,2)', (t) => {
 test('w(0,-1)', (t) => {
   t.is(w(0, -1), 0.3703137182425503)
 })
+
+test('denominator less than threshold', (t) => {
+  t.is(w(0, 10), 0)
+})
diff --git a/test/statistics/wt.test.js b/test/statistics/wt.test.js
index b519606..c7435b2 100644
--- a/test/statistics/wt.test.js
+++ b/test/statistics/wt.test.js
@@ -12,3 +12,11 @@ test('wt(0,2)', (t) => {
 test('wt(0,-1)', (t) => {
   t.is(wt(0, -1), 1)
 })
+
+test('wt(0,0)', (t) => {
+  t.is(wt(0, 0), 1.0)
+})
+
+test('wt(0,10)', (t) => {
+  t.truthy(wt(0, 10) < 0.000000000001)
+})