Migrate run-make/rustdoc-verify-output-files to rmake.rs

Author: GuillaumeGomez

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -227,7 +227,6 @@ run-make/rlib-format-packed-bundled-libs/Makefile
 run-make/rmeta-preferred/Makefile
 run-make/rustc-macro-dep-files/Makefile
 run-make/rustdoc-io-error/Makefile
-run-make/rustdoc-verify-output-files/Makefile
 run-make/sanitizer-cdylib-link/Makefile
 run-make/sanitizer-dylib-link/Makefile
 run-make/sanitizer-staticlib-link/Makefile

tests/run-make/rustdoc-verify-output-files/Makefile

@@ -0,0 +1,43 @@
+use std::fs::copy;
+use std::path::{Path, PathBuf};
+
+use run_make_support::{copy_dir_all, recursive_diff, rustdoc, tmp_dir};
+
+fn generate_docs(out_dir: &Path, json_output: bool) {
+    let mut rustdoc = rustdoc();
+    rustdoc.input("src/lib.rs").crate_name("foobar").crate_type("lib").out_dir(&out_dir);
+    if json_output {
+        rustdoc.arg("-Zunstable-options").output_format("json");
+    }
+    rustdoc.run();
+}
+
+fn main() {
+    let out_dir = tmp_dir().join("rustdoc");
+    let tmp_out_dir = tmp_dir().join("tmp-rustdoc");
+
+    // Generate HTML docs.
+    generate_docs(&out_dir, false);
+
+    // Copy first output for to check if it's exactly same after second compilation.
+    copy_dir_all(&out_dir, &tmp_out_dir);
+
+    // Generate html docs once again on same output.
+    generate_docs(&out_dir, false);
+
+    // Generate json doc on the same output.
+    generate_docs(&out_dir, true);
+
+    // Check if expected json file is generated.
+    assert!(out_dir.join("foobar.json").is_file());
+
+    // Copy first json output to check if it's exactly same after second compilation.
+    copy(out_dir.join("foobar.json"), tmp_out_dir.join("foobar.json")).unwrap();
+
+    // Generate json doc on the same output.
+    generate_docs(&out_dir, true);
+
+    // Check if all docs(including both json and html formats) are still the same after multiple
+    // compilations.
+    recursive_diff(&out_dir, &tmp_out_dir);
+}