From 2a2ce85381df90485df6cf7de4537133b08ae762 Mon Sep 17 00:00:00 2001
From: Dmitriy Pleshevskiy <dmitriy@ideascup.me>
Date: Sun, 23 May 2021 23:28:11 +0300
Subject: [PATCH] refac: add utils for migration list

---
 migra/src/migration.rs | 156 +++++++++++++++++++++++++++++++----------
 1 file changed, 120 insertions(+), 36 deletions(-)

diff --git a/migra/src/migration.rs b/migra/src/migration.rs
index 6f66cb9..a7a82a7 100644
--- a/migra/src/migration.rs
+++ b/migra/src/migration.rs
@@ -1,8 +1,8 @@
+use std::iter::FromIterator;
+
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
 pub struct Migration {
     name: String,
-    upgrade_sql_content: Option<String>,
-    downgrade_sql_content: Option<String>,
 }
 
 impl Migration {
@@ -10,25 +10,6 @@ impl Migration {
     pub fn new(name: &str) -> Self {
         Migration {
             name: name.to_owned(),
-            ..Migration::default()
-        }
-    }
-
-    #[must_use]
-    pub fn with_upgrade(name: &str, up_content: &str) -> Self {
-        Migration {
-            name: name.to_owned(),
-            upgrade_sql_content: Some(up_content.to_owned()),
-            ..Migration::default()
-        }
-    }
-
-    #[must_use]
-    pub fn with_upgrade_and_downgrade(name: &str, up_content: &str, down_content: &str) -> Self {
-        Migration {
-            name: name.to_owned(),
-            upgrade_sql_content: Some(up_content.to_owned()),
-            downgrade_sql_content: Some(down_content.to_owned()),
         }
     }
 
@@ -36,19 +17,9 @@ impl Migration {
     pub fn name(&self) -> &String {
         &self.name
     }
-
-    #[must_use]
-    pub fn upgrade_sql_content(&self) -> Option<&String> {
-        self.upgrade_sql_content.as_ref()
-    }
-
-    #[must_use]
-    pub fn downgrade_sql_content(&self) -> Option<&String> {
-        self.downgrade_sql_content.as_ref()
-    }
 }
 
-#[derive(Debug, Clone, Default)]
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
 pub struct List {
     inner: Vec<Migration>,
 }
@@ -61,27 +32,140 @@ impl<T: AsRef<str>> From<Vec<T>> for List {
     }
 }
 
+impl std::ops::Deref for List {
+    type Target = Vec<Migration>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
 impl List {
     #[must_use]
     pub fn new() -> Self {
         List { inner: Vec::new() }
     }
 
-    pub fn push<T: AsRef<str>>(&mut self, name: &T) {
-        self.inner.push(Migration::new(name.as_ref()))
+    pub fn push(&mut self, migration: Migration) {
+        self.inner.push(migration)
+    }
+
+    pub fn push_name(&mut self, name: &str) {
+        self.inner.push(Migration::new(name))
     }
 
     #[must_use]
-    pub fn contains(&self, name: &str) -> bool {
+    pub fn contains(&self, other_migration: &Migration) -> bool {
+        self.inner
+            .iter()
+            .any(|migration| migration == other_migration)
+    }
+
+    #[must_use]
+    pub fn contains_name(&self, name: &str) -> bool {
         self.inner.iter().any(|migration| migration.name() == name)
     }
 
     #[must_use]
     pub fn maybe_next<'a>(&self, name: &'a str) -> Option<&'a str> {
-        if self.contains(name) {
+        if self.contains_name(name) {
             None
         } else {
             Some(name)
         }
     }
+
+    #[must_use]
+    pub fn exclude(&self, list: &List) -> List {
+        self.iter()
+            .filter(|migration| !list.contains(migration))
+            .collect()
+    }
+}
+
+impl FromIterator<Migration> for List {
+    fn from_iter<I: IntoIterator<Item = Migration>>(iter: I) -> Self {
+        let mut list = List::new();
+
+        for item in iter {
+            list.push(item);
+        }
+
+        list
+    }
+}
+
+impl<'a> FromIterator<&'a Migration> for List {
+    fn from_iter<I: IntoIterator<Item = &'a Migration>>(iter: I) -> Self {
+        let mut list = List::new();
+
+        for item in iter {
+            list.push(item.clone());
+        }
+
+        list
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const FIRST_MIGRATION: &str = "initial_migration";
+    const SECOND_MIGRATION: &str = "new_migration";
+
+    #[test]
+    fn push_migration_to_list() {
+        let mut list = List::new();
+
+        list.push(Migration::new(FIRST_MIGRATION));
+        assert_eq!(list, List::from(vec![FIRST_MIGRATION]));
+
+        list.push(Migration::new(&String::from(SECOND_MIGRATION)));
+        assert_eq!(list, List::from(vec![FIRST_MIGRATION, SECOND_MIGRATION]))
+    }
+
+    #[test]
+    fn push_name_to_list() {
+        let mut list = List::new();
+
+        list.push_name(FIRST_MIGRATION);
+        assert_eq!(list, List::from(vec![FIRST_MIGRATION]));
+
+        list.push_name(&String::from(SECOND_MIGRATION));
+        assert_eq!(list, List::from(vec![FIRST_MIGRATION, SECOND_MIGRATION]))
+    }
+
+    #[test]
+    fn contains_migration() {
+        let list = List::from(vec![FIRST_MIGRATION]);
+
+        assert_eq!(list.contains(&Migration::new(FIRST_MIGRATION)), true);
+        assert_eq!(list.contains(&Migration::new(SECOND_MIGRATION)), false);
+    }
+
+    #[test]
+    fn contains_migration_name() {
+        let list = List::from(vec![FIRST_MIGRATION]);
+
+        assert_eq!(list.contains_name(FIRST_MIGRATION), true);
+        assert_eq!(list.contains_name(SECOND_MIGRATION), false);
+    }
+
+    #[test]
+    fn maybe_next_migration_name() {
+        let list = List::from(vec![FIRST_MIGRATION]);
+
+        assert_eq!(list.maybe_next(FIRST_MIGRATION), None);
+        assert_eq!(list.maybe_next(SECOND_MIGRATION), Some(SECOND_MIGRATION));
+    }
+
+    #[test]
+    fn create_excluded_migration_list() {
+        let all_migrations = List::from(vec![FIRST_MIGRATION, SECOND_MIGRATION]);
+        let applied_migrations = List::from(vec![FIRST_MIGRATION]);
+        let excluded = all_migrations.exclude(&applied_migrations);
+
+        assert_eq!(excluded, List::from(vec![SECOND_MIGRATION]))
+    }
 }