Reorganize taskchampion crate for docs and tests

The public API of the taskchampion crate now contains the expected parts
and no more, and has some better documentation.

This moves the crate's external `tests/` into internal tests, as the
TaskDB is no longer exposed as part of the crate API.

taskchampion/src/replica.rs

@@ -1,21 +1,29 @@
 use crate::errors::Error;
-use crate::operation::Operation;
+use crate::server::Server;
 use crate::task::{Status, Task};
 use crate::taskdb::DB;
-use crate::taskstorage::TaskMap;
+use crate::taskstorage::{Operation, TaskMap, TaskStorage};
 use chrono::Utc;
 use failure::Fallible;
 use std::collections::HashMap;
 use uuid::Uuid;
 
-/// A replica represents an instance of a user's task data.
+/// A replica represents an instance of a user's task data, providing an easy interface
+/// for querying and modifying that data.
 pub struct Replica {
-    taskdb: Box<DB>,
+    taskdb: DB,
 }
 
 impl Replica {
-    pub fn new(taskdb: Box<DB>) -> Replica {
-        return Replica { taskdb };
+    pub fn new(storage: Box<dyn TaskStorage>) -> Replica {
+        return Replica {
+            taskdb: DB::new(storage),
+        };
+    }
+
+    #[cfg(test)]
+    pub fn new_inmemory() -> Replica {
+        Replica::new(Box::new(crate::taskstorage::InMemoryStorage::new()))
     }
 
     /// Update an existing task.  If the value is Some, the property is added or updated.  If the
@@ -45,7 +53,7 @@ impl Replica {
     }
 
     /// Get all tasks represented as a map keyed by UUID
-    pub fn all_tasks<'a>(&'a mut self) -> Fallible<HashMap<Uuid, Task>> {
+    pub fn all_tasks(&mut self) -> Fallible<HashMap<Uuid, Task>> {
         let mut res = HashMap::new();
         for (uuid, tm) in self.taskdb.all_tasks()?.drain(..) {
             res.insert(uuid.clone(), Task::new(uuid.clone(), tm));
@@ -54,7 +62,7 @@ impl Replica {
     }
 
     /// Get the UUIDs of all tasks
-    pub fn all_task_uuids<'a>(&'a mut self) -> Fallible<Vec<Uuid>> {
+    pub fn all_task_uuids(&mut self) -> Fallible<Vec<Uuid>> {
         self.taskdb.all_task_uuids()
     }
 
@@ -124,6 +132,11 @@ impl Replica {
         self.taskdb.apply(Operation::Delete { uuid })
     }
 
+    /// Synchronize this replica against the given server.
+    pub fn sync(&mut self, username: &str, server: &mut dyn Server) -> Fallible<()> {
+        self.taskdb.sync(username, server)
+    }
+
     /// Perform "garbage collection" on this replica.  In particular, this renumbers the working
     /// set to contain only pending tasks.
     pub fn gc(&mut self) -> Fallible<()> {
@@ -138,12 +151,11 @@ impl Replica {
 mod tests {
     use super::*;
     use crate::task::Status;
-    use crate::taskdb::DB;
     use uuid::Uuid;
 
     #[test]
     fn new_task() {
-        let mut rep = Replica::new(DB::new_inmemory().into());
+        let mut rep = Replica::new_inmemory();
         let uuid = Uuid::new_v4();
 
         let t = rep
@@ -156,7 +168,7 @@ mod tests {
 
     #[test]
     fn modify_task() {
-        let mut rep = Replica::new(DB::new_inmemory().into());
+        let mut rep = Replica::new_inmemory();
         let uuid = Uuid::new_v4();
 
         let t = rep
@@ -183,7 +195,7 @@ mod tests {
 
     #[test]
     fn delete_task() {
-        let mut rep = Replica::new(DB::new_inmemory().into());
+        let mut rep = Replica::new_inmemory();
         let uuid = Uuid::new_v4();
 
         rep.new_task(uuid.clone(), Status::Pending, "a task".into())
@@ -195,7 +207,7 @@ mod tests {
 
     #[test]
     fn get_and_modify() {
-        let mut rep = Replica::new(DB::new_inmemory().into());
+        let mut rep = Replica::new_inmemory();
         let uuid = Uuid::new_v4();
 
         rep.new_task(uuid.clone(), Status::Pending, "another task".into())
@@ -215,7 +227,7 @@ mod tests {
 
     #[test]
     fn new_pending_adds_to_working_set() {
-        let mut rep = Replica::new(DB::new_inmemory().into());
+        let mut rep = Replica::new_inmemory();
         let uuid = Uuid::new_v4();
 
         rep.new_task(uuid.clone(), Status::Pending, "to-be-pending".into())
@@ -233,7 +245,7 @@ mod tests {
 
     #[test]
     fn get_does_not_exist() {
-        let mut rep = Replica::new(DB::new_inmemory().into());
+        let mut rep = Replica::new_inmemory();
         let uuid = Uuid::new_v4();
         assert_eq!(rep.get_task(&uuid).unwrap(), None);
     }