Add tests for tab width.

tests/test_template

@@ -1,3 +1,5 @@
+// TODO: Investigate writing a proc macro to make specifying these permutations easier.
+
 {expect_fail}
 #[test]
 fn autogen_{name}() -> Result<(), Box<dyn std::error::Error>> {{
@@ -20,3 +22,31 @@ fn autogen_la_{name}() -> Result<(), Box<dyn std::error::Error>> {{
     organic::compare::run_anonymous_compare_with_settings(org_contents.as_str(), &global_settings)?;
     Ok(())
 }}
+
+{expect_fail}
+#[test]
+fn autogen_t1_{name}() -> Result<(), Box<dyn std::error::Error>> {{
+    let org_path = "{path}";
+    let org_contents = std::fs::read_to_string(org_path).expect("Read org file.");
+    let global_settings = {{
+        let mut global_settings = organic::GlobalSettings::default();
+        global_settings.tab_width = 1;
+        global_settings
+    }};
+    organic::compare::run_anonymous_compare_with_settings(org_contents.as_str(), &global_settings)?;
+    Ok(())
+}}
+
+{expect_fail}
+#[test]
+fn autogen_t16_{name}() -> Result<(), Box<dyn std::error::Error>> {{
+    let org_path = "{path}";
+    let org_contents = std::fs::read_to_string(org_path).expect("Read org file.");
+    let global_settings = {{
+        let mut global_settings = organic::GlobalSettings::default();
+        global_settings.tab_width = 16;
+        global_settings
+    }};
+    organic::compare::run_anonymous_compare_with_settings(org_contents.as_str(), &global_settings)?;
+    Ok(())
+}}