Switch character data type to an enum, including schema patch.

Schema patch required because the diesel enum derive crate does not
seem to deal with print-schema for sqlite.

Cargo.lock

@@ -342,6 +342,18 @@ dependencies = [
  "r2d2",
 ]
 
+[[package]]
+name = "diesel-derive-enum"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "703e71c268ea2d8da9c0ab0b40d8b217179ee622209c170875d24443193a0dfb"
+dependencies = [
+ "heck",
+ "proc-macro2 1.0.24",
+ "quote 1.0.7",
+ "syn 1.0.53",
+]
+
 [[package]]
 name = "diesel_derives"
 version = "1.4.1"
@@ -1436,6 +1448,7 @@ name = "tenebrous-sheets"
 version = "0.1.0"
 dependencies = [
  "diesel",
+ "diesel-derive-enum",
  "log 0.4.11",
  "prost",
  "prost-build",

Cargo.toml

@@ -14,6 +14,7 @@ serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 diesel = "1.4"
+diesel-derive-enum = { version = "1", features = ["sqlite"] }
 thiserror = "1.0"
 rust-argon2 = "0.8"
 log = "0.4"

diesel.toml

@@ -3,3 +3,5 @@
 
 [print_schema]
 file = "src/schema.rs"
+import_types = ["diesel::sql_types::*", "crate::models::characters::*"]
+patch_file = "src/schema.patch"

migrations/2020-12-02-213704_characters/up.sql

@@ -3,7 +3,7 @@ CREATE TABLE characters(
        user_id INTEGER NOT NULL,
        viewable BOOLEAN NOT NULL,
        character_name TEXT NOT NULL,
-       data_type TEXT NOT NULL,
+       data_type TEXT CHECK(data_type IN ('chronicles_of_darkness_v1', 'changeling_v1')) NOT NULL,
        data_version INTEGER NOT NULL,
        data BLOB NOT NULL
 );

src/models/characters.rs

@@ -1,5 +1,6 @@
 use crate::models::users::User;
 use crate::schema::characters;
+use diesel_derive_enum::DbEnum;
 use serde_derive::Serialize;
 
 /// Control system visibility of a character for a particular user.
@@ -29,6 +30,12 @@ pub(crate) trait Visibility {
     }
 }
 
+#[derive(DbEnum, Debug, Serialize, PartialEq)]
+pub enum CharacterDataType {
+    ChroniclesOfDarknessV1,
+    ChangelingV1,
+}
+
 /// An entry that appears in a user's character list. Properties are
 /// in order of table columns.
 #[derive(Serialize, Debug, Queryable)]
@@ -37,7 +44,7 @@ pub struct Character {
     pub user_id: i32,
     pub viewable: bool,
     pub character_name: String,
-    pub data_type: String,
+    pub data_type: CharacterDataType,
     pub data_version: i32,
     pub data: Vec<u8>,
 }
@@ -58,7 +65,7 @@ pub struct StrippedCharacter {
     pub user_id: i32,
     pub viewable: bool,
     pub character_name: String,
-    pub data_type: String,
+    pub data_type: CharacterDataType,
     pub data_version: i32,
 }
 
@@ -80,7 +87,7 @@ pub struct NewCharacter<'a> {
     pub user_id: i32,
     pub viewable: bool,
     pub character_name: &'a str,
-    pub data_type: &'a str,
+    pub data_type: CharacterDataType,
     pub data_version: i32,
     pub data: &'a [u8],
 }

src/schema.patch

@@ -0,0 +1,18 @@
+This patch converts the generated schema to an enum type.
+--- a/src/schema.rs
++++ b/src/schema.rs
+@@ -4,13 +4,13 @@ table! {
+ 
+     characters (id) {
+         id -> Integer,
+         user_id -> Integer,
+         viewable -> Bool,
+         character_name -> Text,
+-        data_type -> Text,
++        data_type -> CharacterDataTypeMapping,
+         data_version -> Integer,
+         data -> Binary,
+     }
+ }
+ 
+ table! {

src/schema.rs

@@ -1,16 +1,22 @@
 table! {
+    use diesel::sql_types::*;
+    use crate::models::characters::*;
+
     characters (id) {
         id -> Integer,
         user_id -> Integer,
         viewable -> Bool,
         character_name -> Text,
-        data_type -> Text,
+        data_type -> CharacterDataTypeMapping,
         data_version -> Integer,
         data -> Binary,
     }
 }
 
 table! {
+    use diesel::sql_types::*;
+    use crate::models::characters::*;
+
     users (id) {
         id -> Integer,
         username -> Text,