From c719978d798b5d94a9609e15845aeb69682d0790 Mon Sep 17 00:00:00 2001
From: Victor Lin <13424970+victorlin@users.noreply.github.com>
Date: Mon, 21 Oct 2024 09:17:21 -0700
Subject: [PATCH 1/2] Use type-safe equality check for narrative title
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Previous check of != null would fail on non-null falsey values. In
practice, I don't think Element.querySelector can return any falsey
values other than null. Nevertheless, it's good to be explicit that we
only care about null, i.e. no matches are found.¹

¹ https://developer.mozilla.org/en-US/docs/Web/API/Element/querySelector#return_value
---
 src/util/parseNarrative.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/parseNarrative.js b/src/util/parseNarrative.js
index d426a35a7..5ab213539 100644
--- a/src/util/parseNarrative.js
+++ b/src/util/parseNarrative.js
@@ -91,7 +91,7 @@ function* parseNarrativeBody(markdown, fallbackDataset, markdownParser) {
   const titleLinkSelector = "h1 > a:only-child";
   const isTitle = (node) =>
     node.nodeType === Node.ELEMENT_NODE &&
-    node.querySelector(titleLinkSelector) != null;
+    node.querySelector(titleLinkSelector) !== null;
 
   for (const titleLink of doc.querySelectorAll(titleLinkSelector)) {
     const slide = doc.createElement("slide");

From a2e4c548957d1dd6c7eb444ed69d4eb8a883fbd3 Mon Sep 17 00:00:00 2001
From: Victor Lin <13424970+victorlin@users.noreply.github.com>
Date: Mon, 21 Oct 2024 09:10:52 -0700
Subject: [PATCH 2/2] Enforce usage of type-safe equality operators

Using == / != is a source of bugs.

Rule doc page: https://eslint.org/docs/latest/rules/eqeqeq
---
 .eslintrc.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.eslintrc.yaml b/.eslintrc.yaml
index 3f385f2fb..51926d896 100644
--- a/.eslintrc.yaml
+++ b/.eslintrc.yaml
@@ -21,6 +21,7 @@ globals:
 
 rules:
   # Code quality rules
+  eqeqeq: error
   "@typescript-eslint/no-empty-function": ["error", { "allow": ["arrowFunctions"] }]
   "@typescript-eslint/no-explicit-any": off # Allow explicit any to make incremental TypeScript adoption easier.
   no-unused-vars: off