From 0215817262687fa2d1b3901502fdcd50b2264eef Mon Sep 17 00:00:00 2001
From: Matthias Beyer <mail@beyermatthias.de>
Date: Sat, 15 Jul 2017 00:05:05 +0200
Subject: [PATCH] Add quickcheck-based test for link removal

---
 libimagentrylink/Cargo.toml      |  3 ++
 libimagentrylink/src/internal.rs | 79 ++++++++++++++++++++++++++++++++
 libimagentrylink/src/lib.rs      |  4 ++
 3 files changed, 86 insertions(+)

diff --git a/libimagentrylink/Cargo.toml b/libimagentrylink/Cargo.toml
index 193f5108..67723efc 100644
--- a/libimagentrylink/Cargo.toml
+++ b/libimagentrylink/Cargo.toml
@@ -23,6 +23,9 @@ rust-crypto = "0.2"
 env_logger = "0.3"
 is-match = "0.1"
 
+[dev-dependencies]
+quickcheck = "0.3"
+
 [dependencies.libimagstore]
 path = "../libimagstore"
 
diff --git a/libimagentrylink/src/internal.rs b/libimagentrylink/src/internal.rs
index 62003777..9507698f 100644
--- a/libimagentrylink/src/internal.rs
+++ b/libimagentrylink/src/internal.rs
@@ -1056,5 +1056,84 @@ mod test {
         assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
     }
 
+    quickcheck! {
+
+        // This creates `removals.len() * 10` entries in the store and links all of them to a
+        // test entry.
+        // After that, each entry from the to-link-entries list which is hit by an index from
+        // `removals` is unlinked again and a number of checks run for the testing entry:
+        //
+        //     * Are all other entries still linked (two-way-check)
+        //     * Is the number of links in the testing entry smaller than before
+        //     * Is the just unlinked entry not linked
+        //
+        // I'm not sure whether using quickcheck is the right approach here, but it is the easiest
+        // way to create a random number of to-remove-entries where I don't know which ones get
+        // removed.
+        fn test_random_linking(removals: Vec<usize>) -> bool {
+            use std::collections::hash_map::DefaultHasher;
+            use std::hash::Hash;
+            use std::hash::Hasher;
+            use itertools::Itertools;
+
+            setup_logging();
+
+            let num_removals    = removals.len();
+            let num_tmp_entries = num_removals * 10;
+            let removals        = removals
+                .into_iter()
+                .map(|r| r % num_tmp_entries)
+                .unique()
+                .collect::<Vec<usize>>();
+
+            let store = get_store();
+
+            let test_entry_name = {
+                let mut hasher = DefaultHasher::new();
+                removals.hash(&mut hasher);
+                let name_ext : u64 = hasher.finish();
+                format!("test-{}", name_ext)
+            };
+
+            let mut test_entry = store.retrieve(PathBuf::from(test_entry_name)).unwrap();
+
+            let mut tmp_entries = Vec::with_capacity(num_tmp_entries);
+
+            for i in 0..num_tmp_entries {
+                let mut entry = store.retrieve(PathBuf::from(format!("tmp-{}", i))).unwrap();
+                assert!(test_entry.add_internal_link(&mut entry).is_ok(),
+                        format!("Adding entry did not work: {:?} -> {:?}", test_entry, entry));
+                tmp_entries.push(entry);
+            }
+
+            let link_count = test_entry.get_internal_links().unwrap().count();
+
+            assert_eq!(link_count, num_tmp_entries,
+                        "Numbers of links in test_entry should be: {:?} but is {:?}: {:?}",
+                        num_tmp_entries, link_count,
+                        test_entry.get_internal_links().unwrap().collect::<Vec<_>>());
+
+            for index in removals {
+                let num_links = test_entry.get_internal_links().unwrap().count();
+
+                debug!("Removing link: {:?}", tmp_entries[index]);
+                assert!(test_entry.remove_internal_link(&mut tmp_entries[index]).is_ok(),
+                        format!("Removing link to test entry failed: {:?}", tmp_entries[index]));
+
+                let link_count = test_entry.get_internal_links().unwrap().count();
+                assert_eq!(link_count, num_links - 1,
+                            "Numbers of links in test_entry should be: {:?} but is {:?}: {:?}",
+                            num_links - 1, link_count,
+                            test_entry.get_internal_links().unwrap().collect::<Vec<_>>());
+
+                for internal_link in test_entry.get_internal_links().unwrap() {
+                    assert!(tmp_entries.iter().any(|tmp| internal_link.eq_store_id(tmp.get_location())));
+                }
+            }
+
+            true
+        }
+    }
+
 }
 
diff --git a/libimagentrylink/src/lib.rs b/libimagentrylink/src/lib.rs
index 2ed8b6ba..eab4ea9e 100644
--- a/libimagentrylink/src/lib.rs
+++ b/libimagentrylink/src/lib.rs
@@ -42,6 +42,10 @@ extern crate crypto;
 #[cfg(test)]
 extern crate env_logger;
 
+#[cfg(test)]
+#[macro_use]
+extern crate quickcheck;
+
 #[macro_use] extern crate libimagstore;
 #[macro_use] extern crate libimagerror;
 extern crate libimagutil;