From 6549bcc197d34571f804db16f72c85b738268ed0 Mon Sep 17 00:00:00 2001
From: Quincy Morgan <2046746+quincylvania@users.noreply.github.com>
Date: Fri, 23 Oct 2020 11:27:32 -0400
Subject: [PATCH] Enable no-eq-null eslint rule

---
 .eslintrc                     | 1 +
 modules/util/get_set_value.js | 4 ++--
 modules/util/zoom_pan.js      | 6 +++---
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/.eslintrc b/.eslintrc
index c7a7f3374..376e73565 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -29,6 +29,7 @@
         "no-console": "warn",
         "no-constructor-return": "error",
         "no-div-regex": "error",
+        "no-eq-null": "error",
         "no-eval": "error",
         "no-extend-native": "error",
         "no-extra-bind": "error",
diff --git a/modules/util/get_set_value.js b/modules/util/get_set_value.js
index e77e84d49..d55f805ae 100644
--- a/modules/util/get_set_value.js
+++ b/modules/util/get_set_value.js
@@ -14,14 +14,14 @@ export function utilGetSetValue(selection, value) {
 
         function valueFunction() {
             var x = value.apply(this, arguments);
-            if (x == null) {
+            if (x === null || x === undefined) {
                 delete this.value;
             } else if (this.value !== x) {
                 this.value = x;
             }
         }
 
-        return value == null
+        return (value === null || value === undefined)
             ? valueNull : (typeof value === 'function'
             ? valueFunction : valueConstant);
     }
diff --git a/modules/util/zoom_pan.js b/modules/util/zoom_pan.js
index fa473489b..ee69ed73b 100644
--- a/modules/util/zoom_pan.js
+++ b/modules/util/zoom_pan.js
@@ -95,7 +95,7 @@ export function utilZoomPan() {
     zoom.transform(selection, function() {
       var e = extent.apply(this, arguments),
           t0 = _transform,
-          p0 = p == null ? centroid(e) : typeof p === 'function' ? p.apply(this, arguments) : p,
+          p0 = !p ? centroid(e) : typeof p === 'function' ? p.apply(this, arguments) : p,
           p1 = t0.invert(p0),
           k1 = typeof k === 'function' ? k.apply(this, arguments) : k;
       return constrain(translate(scale(t0, k1), p0, p1), e, translateExtent);
@@ -115,7 +115,7 @@ export function utilZoomPan() {
     zoom.transform(selection, function() {
       var e = extent.apply(this, arguments),
           t = _transform,
-          p0 = p == null ? centroid(e) : typeof p === 'function' ? p.apply(this, arguments) : p;
+          p0 = !p ? centroid(e) : typeof p === 'function' ? p.apply(this, arguments) : p;
       return constrain(d3_zoomIdentity.translate(p0[0], p0[1]).scale(t.k).translate(
         typeof x === 'function' ? -x.apply(this, arguments) : -x,
         typeof y === 'function' ? -y.apply(this, arguments) : -y
@@ -146,7 +146,7 @@ export function utilZoomPan() {
               args = arguments,
               g = gesture(that, args),
               e = extent.apply(that, args),
-              p = point == null ? centroid(e) : typeof point === 'function' ? point.apply(that, args) : point,
+              p = !point ? centroid(e) : typeof point === 'function' ? point.apply(that, args) : point,
               w = Math.max(e[1][0] - e[0][0], e[1][1] - e[0][1]),
               a = _transform,
               b = typeof transform === 'function' ? transform.apply(that, args) : transform,