Add rollback-until-just-after function for #200 (#201)

Co-authored-by: Vincent Pizzo <[email protected]>

src/migratus/core.clj

@@ -215,3 +215,16 @@
                    sort
                    (take-while #(< % migration-id))
                    (apply up config))))
+
+(defn rollback-until-just-after
+  "Migrate down all migrations after migration-id. This only considers completed
+  migrations, and will not migrate up."
+  [config migration-id]
+  (with-store [store (proto/make-store config)]
+              (->> (completed-migrations config store)
+                   (map proto/id)
+                   distinct
+                   sort
+                   reverse
+                   (take-while #(> % migration-id))
+                   (apply down config))))

test/migratus/test/database.clj

@@ -188,6 +188,18 @@
   (is (test-sql/verify-table-exists? config "quux"))
   (is (test-sql/verify-table-exists? config "quux2")))
 
+(deftest test-rollback-until-just-after
+  (core/migrate config)
+  (is (test-sql/verify-table-exists? config "foo"))
+  (is (test-sql/verify-table-exists? config "bar"))
+  (is (test-sql/verify-table-exists? config "quux"))
+  (is (test-sql/verify-table-exists? config "quux2"))
+  (core/rollback-until-just-after config 20111202110600)
+  (is (test-sql/verify-table-exists? config "foo"))
+  (is (not (test-sql/verify-table-exists? config "bar")))
+  (is (not (test-sql/verify-table-exists? config "quux")))
+  (is (not (test-sql/verify-table-exists? config "quux2"))))
+
 (deftest test-migration-ignored-when-already-reserved
   (test-with-store
     (proto/make-store config)