diff --git a/tests/rendered_output.rs b/tests/rendered_output.rs
index 696de857..c7618335 100644
--- a/tests/rendered_output.rs
+++ b/tests/rendered_output.rs
@@ -5,7 +5,6 @@ use crate::dummy_book::{assert_contains_strings, DummyBook};
 use anyhow::Context;
 use mdbook::config::Config;
 use mdbook::errors::*;
-use mdbook::utils::fs::write_file;
 use mdbook::MDBook;
 use pretty_assertions::assert_eq;
 use select::document::Document;
@@ -13,8 +12,6 @@ use select::predicate::{Attr, Class, Name, Predicate};
 use std::ffi::OsStr;
 use std::fs;
 use std::path::Path;
-use std::str::FromStr;
-use tempfile::Builder as TempFileBuilder;
 use walkdir::{DirEntry, WalkDir};
 
 const BOOK_ROOT: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/dummy_book");
@@ -172,28 +169,6 @@ fn toc_fallback_html() -> Result<Document> {
     Ok(Document::from(html.as_str()))
 }
 
-#[test]
-fn check_second_toc_level() {
-    let doc = toc_js_html().unwrap();
-    let mut should_be = Vec::from(TOC_SECOND_LEVEL);
-    should_be.sort_unstable();
-
-    let pred = descendants!(
-        Class("chapter"),
-        Name("li"),
-        Name("li"),
-        Name("a").and(Class("toggle").not())
-    );
-
-    let mut children_of_children: Vec<_> = doc
-        .find(pred)
-        .map(|elem| elem.text().trim().to_string())
-        .collect();
-    children_of_children.sort();
-
-    assert_eq!(children_of_children, should_be);
-}
-
 #[test]
 fn check_first_toc_level() {
     let doc = toc_js_html().unwrap();
diff --git a/tests/testsuite/main.rs b/tests/testsuite/main.rs
index 162f850a..cc9bef92 100644
--- a/tests/testsuite/main.rs
+++ b/tests/testsuite/main.rs
@@ -19,6 +19,7 @@ mod rendering;
 mod search;
 mod test;
 mod theme;
+mod toc;
 
 mod prelude {
     pub use crate::book_test::BookTest;
diff --git a/tests/testsuite/toc.rs b/tests/testsuite/toc.rs
new file mode 100644
index 00000000..2787b995
--- /dev/null
+++ b/tests/testsuite/toc.rs
@@ -0,0 +1,55 @@
+//! Tests for table of contents (sidebar).
+
+use crate::prelude::*;
+use select::document::Document;
+use select::predicate::{Class, Name, Predicate};
+
+const TOC_SECOND_LEVEL: &[&str] = &[
+    "1.1. Nested Index",
+    "1.2. Nested two",
+    "3.1. Deep Nest 2",
+    "3.1.1. Deep Nest 3",
+];
+
+/// Apply a series of predicates to some root predicate, where each
+/// successive predicate is the descendant of the last one. Similar to how you
+/// might do `ul.foo li a` in CSS to access all anchor tags in the `foo` list.
+macro_rules! descendants {
+    ($root:expr, $($child:expr),*) => {
+        $root
+        $(
+            .descendant($child)
+        )*
+    };
+}
+
+/// Read the TOC (`book/toc.js`) nested HTML and expose it as a DOM which we
+/// can search with the `select` crate
+fn toc_js_html() -> Document {
+    let mut test = BookTest::from_dir("toc/basic_toc");
+    test.build();
+    let html = test.toc_js_html();
+    Document::from(html.as_str())
+}
+
+#[test]
+fn check_second_toc_level() {
+    let doc = toc_js_html();
+    let mut should_be = Vec::from(TOC_SECOND_LEVEL);
+    should_be.sort_unstable();
+
+    let pred = descendants!(
+        Class("chapter"),
+        Name("li"),
+        Name("li"),
+        Name("a").and(Class("toggle").not())
+    );
+
+    let mut children_of_children: Vec<_> = doc
+        .find(pred)
+        .map(|elem| elem.text().trim().to_string())
+        .collect();
+    children_of_children.sort();
+
+    assert_eq!(children_of_children, should_be);
+}
diff --git a/tests/testsuite/toc/basic_toc/book.toml b/tests/testsuite/toc/basic_toc/book.toml
new file mode 100644
index 00000000..cebbd270
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/book.toml
@@ -0,0 +1,2 @@
+[book]
+title = "basic_toc"
diff --git a/tests/testsuite/toc/basic_toc/src/README.md b/tests/testsuite/toc/basic_toc/src/README.md
new file mode 100644
index 00000000..8ad6862f
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/README.md
@@ -0,0 +1 @@
+# With Readme
diff --git a/tests/testsuite/toc/basic_toc/src/SUMMARY.md b/tests/testsuite/toc/basic_toc/src/SUMMARY.md
new file mode 100644
index 00000000..9060ce68
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/SUMMARY.md
@@ -0,0 +1,23 @@
+# Summary
+
+[Prefix 1](prefix1.md)
+[Prefix 2](prefix2.md)
+
+- [With Readme](README.md)
+    - [Nested Index](nested/index.md)
+    - [Nested two](nested/two.md)
+- [Draft]()
+
+---
+
+# Deep Nest
+
+- [Deep Nest 1](deep/index.md)
+    - [Deep Nest 2](deep/a/index.md)
+        - [Deep Nest 3](deep/a/b/index.md)
+            [Deep Nest 4](deep/a/b/c/index.md)
+
+---
+
+[Suffix 1](suffix1.md)
+[Suffix 2](suffix2.md)
diff --git a/tests/testsuite/toc/basic_toc/src/deep/a/b/index.md b/tests/testsuite/toc/basic_toc/src/deep/a/b/index.md
new file mode 100644
index 00000000..2bd51169
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/deep/a/b/index.md
@@ -0,0 +1 @@
+# Deep Nest 3
diff --git a/tests/testsuite/toc/basic_toc/src/deep/a/index.md b/tests/testsuite/toc/basic_toc/src/deep/a/index.md
new file mode 100644
index 00000000..01fcd70c
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/deep/a/index.md
@@ -0,0 +1 @@
+# Deep Nest 2
diff --git a/tests/testsuite/toc/basic_toc/src/deep/index.md b/tests/testsuite/toc/basic_toc/src/deep/index.md
new file mode 100644
index 00000000..847f336d
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/deep/index.md
@@ -0,0 +1 @@
+# Deep Nest 1
diff --git a/tests/testsuite/toc/basic_toc/src/nested/index.md b/tests/testsuite/toc/basic_toc/src/nested/index.md
new file mode 100644
index 00000000..ecbbbc86
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/nested/index.md
@@ -0,0 +1 @@
+# Nested Index
diff --git a/tests/testsuite/toc/basic_toc/src/nested/two.md b/tests/testsuite/toc/basic_toc/src/nested/two.md
new file mode 100644
index 00000000..e600bff7
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/nested/two.md
@@ -0,0 +1 @@
+# Nested two
diff --git a/tests/testsuite/toc/basic_toc/src/prefix1.md b/tests/testsuite/toc/basic_toc/src/prefix1.md
new file mode 100644
index 00000000..4ddb4143
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/prefix1.md
@@ -0,0 +1 @@
+# Prefix 1
diff --git a/tests/testsuite/toc/basic_toc/src/prefix2.md b/tests/testsuite/toc/basic_toc/src/prefix2.md
new file mode 100644
index 00000000..11ff4958
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/prefix2.md
@@ -0,0 +1 @@
+# Prefix 2
diff --git a/tests/testsuite/toc/basic_toc/src/suffix1.md b/tests/testsuite/toc/basic_toc/src/suffix1.md
new file mode 100644
index 00000000..59a81900
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/suffix1.md
@@ -0,0 +1 @@
+# Suffix 1
diff --git a/tests/testsuite/toc/basic_toc/src/suffix2.md b/tests/testsuite/toc/basic_toc/src/suffix2.md
new file mode 100644
index 00000000..2bf99ebe
--- /dev/null
+++ b/tests/testsuite/toc/basic_toc/src/suffix2.md
@@ -0,0 +1 @@
+# Suffix 2