Write preprocessed content to file before testing with rustdoc

Fixes #855.

src/book/mod.rs

@@ -242,13 +242,12 @@ impl MDBook {
             if let BookItem::Chapter(ref ch) = *item {
                 if !ch.path.as_os_str().is_empty() {
                     let path = self.source_dir().join(&ch.path);
-                    let content = utils::fs::file_to_string(&path)?;
                     info!("Testing file: {:?}", path);
 
                     // write preprocessed file to tempdir
                     let path = temp_dir.path().join(&ch.path);
                     let mut tmpf = utils::fs::create_file(&path)?;
-                    tmpf.write_all(content.as_bytes())?;
+                    tmpf.write_all(ch.content.as_bytes())?;
 
                     let output = Command::new("rustdoc")
                         .arg(&path)

tests/dummy_book/mod.rs

@@ -58,8 +58,11 @@ impl DummyBook {
         })?;
 
         let sub_pattern = if self.passing_test { "true" } else { "false" };
-        let file_containing_test = temp.path().join("src/first/nested.md");
+        let files_containing_tests = ["src/first/nested.md", "src/first/nested-test.rs"];
-        replace_pattern_in_file(&file_containing_test, "$TEST_STATUS", sub_pattern)?;
+        for file in &files_containing_tests {
+            let path_containing_tests = temp.path().join(file);
+            replace_pattern_in_file(&path_containing_tests, "$TEST_STATUS", sub_pattern)?;
+        }
 
         Ok(temp)
     }

tests/dummy_book/src/first/nested-test.rs

@@ -0,0 +1 @@
+assert!($TEST_STATUS);

tests/dummy_book/src/first/nested.md

@@ -7,3 +7,7 @@ assert!($TEST_STATUS);
 ```
 
 ## Some Section
+
+```rust
+{{#include nested-test.rs}}
+```

tests/searchindex_fixture.json

@@ -46,7 +46,7 @@
           "title": 2
         },
         "5": {
-          "body": 0,
+          "body": 1,
           "breadcrumbs": 3,
           "title": 1
         },
@@ -109,7 +109,7 @@
           "title": "Nested Chapter"
         },
         "5": {
-          "body": "",
+          "body": "assert!(true);",
           "breadcrumbs": "First Chapter » Some Section",
           "id": "5",
           "title": "Some Section"
@@ -177,10 +177,13 @@
                               "df": 0,
                               "docs": {},
                               "u": {
-                                "df": 1,
+                                "df": 2,
                                 "docs": {
                                   "4": {
                                     "tf": 1.0
+                                  },
+                                  "5": {
+                                    "tf": 1.0
                                   }
                                 }
                               }
@@ -1336,10 +1339,13 @@
                               "df": 0,
                               "docs": {},
                               "u": {
-                                "df": 1,
+                                "df": 2,
                                 "docs": {
                                   "4": {
                                     "tf": 1.0
+                                  },
+                                  "5": {
+                                    "tf": 1.0
                                   }
                                 }
                               }