Add test to make sure pre-processors are being run

src/lib.rs

@@ -118,7 +118,7 @@ extern crate toml_query;
 #[macro_use]
 extern crate pretty_assertions;
 
-mod preprocess;
+pub mod preprocess;
 pub mod book;
 pub mod config;
 pub mod renderer;

tests/testing.rs

@@ -1,10 +1,18 @@
 extern crate mdbook;
+#[macro_use]
+extern crate lazy_static;
 
 mod dummy_book;
 
 use dummy_book::DummyBook;
-use mdbook::MDBook;
 
+use mdbook::MDBook;
+use mdbook::preprocess::{Preprocessor, PreprocessorContext};
+use mdbook::book::Book;
+use mdbook::config::Config;
+use mdbook::errors::*;
+
+use std::sync::Mutex;
 
 #[test]
 fn mdbook_can_correctly_test_a_passing_book() {
@@ -21,3 +29,33 @@ fn mdbook_detects_book_with_failing_tests() {
 
     assert!(md.test(vec![]).is_err());
 }
+
+#[test]
+fn mdbook_runs_preprocessors() {
+
+    lazy_static! {
+        static ref HAS_RUN: Mutex<bool> = Mutex::new(false);
+    }
+
+    struct DummyPreprocessor;
+
+    impl Preprocessor for DummyPreprocessor {
+        fn name(&self) -> &str {
+            "dummy"
+        }
+
+        fn run(&self, _ctx: &PreprocessorContext, _book: &mut Book) -> Result<()> {
+            *HAS_RUN.lock().unwrap() = true;
+            Ok(())
+        }
+    }
+
+    let temp = DummyBook::new().build().unwrap();
+    let cfg = Config::default();
+
+    let mut book = MDBook::load_with_config(temp.path(), cfg).unwrap();
+    book.with_preprecessor(DummyPreprocessor);
+    book.build().unwrap();
+
+    assert!(*HAS_RUN.lock().unwrap())
+}