Unicode normalization on input.

This normalizes the following values:

* login names
* passwords
* channel names
* message bodies, because why not

The goal here is to have a canonical representation of these values, so that, for example, the service does not inadvertently host two channels whose names are semantically identical but differ in the specifics of how diacritics are encoded, or two users whose names are identical.

Normalization is done on input from the wire, using Serde hooks, and when reading from the database. The `crate::nfc::String` type implements these normalizations (as well as normalizing whenever converted from a `std::string::String` generally).

This change does not cover:

* Trying to cope with passwords that were created as non-normalized strings, which are now non-verifiable as all the paths to verify passwords normalize the input.
* Trying to ensure that non-normalized data in the database compares reasonably to normalized data. Fortunately, we don't _do_ very many string comparisons (I think only login names), so this isn't a huge deal at this stage. Login names will probably have to Get Fixed later on, when we figure out how to handle case folding for login name verification.

3 files changed, 14 insertions, 14 deletions

diff --git a/src/test/fixtures/channel.rs b/src/test/fixtures/channel.rs
index a1dda61..024ac1b 100644
--- a/src/test/fixtures/channel.rs
+++ b/src/test/fixtures/channel.rs
@@ -8,7 +8,7 @@ use rand;
 
 use crate::{
     app::App,
-    channel::{self, Channel},
+    channel::{self, Channel, Name},
     clock::RequestedAt,
     event::Event,
 };
@@ -21,13 +21,13 @@ pub async fn create(app: &App, created_at: &RequestedAt) -> Channel {
         .expect("should always succeed if the channel is actually new")
 }
 
-pub fn propose() -> String {
-    rand::random::<Name>().to_string()
+pub fn propose() -> Name {
+    rand::random::<NameTemplate>().to_string().into()
 }
 
-struct Name(String);
+struct NameTemplate(String);
 faker_impl_from_templates! {
-    Name; "{} {}", CityName, FullName;
+    NameTemplate; "{} {}", CityName, FullName;
 }
 
 pub fn events(event: Event) -> future::Ready<Option<channel::Event>> {
diff --git a/src/test/fixtures/login.rs b/src/test/fixtures/login.rs
index b6766fe..0a42320 100644
--- a/src/test/fixtures/login.rs
+++ b/src/test/fixtures/login.rs
@@ -4,7 +4,7 @@ use uuid::Uuid;
 use crate::{
     app::App,
     clock::RequestedAt,
-    login::{self, Login, Password},
+    login::{self, Login, Name, Password},
 };
 
 pub async fn create_with_password(app: &App, created_at: &RequestedAt) -> (Login, Password) {
@@ -29,16 +29,16 @@ pub async fn create(app: &App, created_at: &RequestedAt) -> Login {
 pub fn fictitious() -> Login {
     Login {
         id: login::Id::generate(),
-        name: name(),
+        name: propose_name(),
     }
 }
 
-pub fn propose() -> (String, Password) {
-    (name(), propose_password())
+pub fn propose() -> (Name, Password) {
+    (propose_name(), propose_password())
 }
 
-fn name() -> String {
-    rand::random::<internet::Username>().to_string()
+fn propose_name() -> Name {
+    rand::random::<internet::Username>().to_string().into()
 }
 
 pub fn propose_password() -> Password {
diff --git a/src/test/fixtures/message.rs b/src/test/fixtures/message.rs
index eb00e7c..c450bce 100644
--- a/src/test/fixtures/message.rs
+++ b/src/test/fixtures/message.rs
@@ -8,7 +8,7 @@ use crate::{
     clock::RequestedAt,
     event::Event,
     login::Login,
-    message::{self, Message},
+    message::{self, Body, Message},
 };
 
 pub async fn send(app: &App, channel: &Channel, login: &Login, sent_at: &RequestedAt) -> Message {
@@ -20,8 +20,8 @@ pub async fn send(app: &App, channel: &Channel, login: &Login, sent_at: &Request
         .expect("should succeed if the channel exists")
 }
 
-pub fn propose() -> String {
-    rand::random::<Paragraphs>().to_string()
+pub fn propose() -> Body {
+    rand::random::<Paragraphs>().to_string().into()
 }
 
 pub fn events(event: Event) -> future::Ready<Option<message::Event>> {