jiff-diesel: add integration crate for Diesel

This is like #240, but adds a crate with wrapper types that implements
Diesel traits. Unlike with SQLx, and unless I'm missing something,
Diesel actually exposes enough of an API to implement datetime support
for MySQL. So that's included here.

Diesel does seem to use some internal privileged APIs for its own
`chrono` and `time` integration that avoids unnecessary allocations
when parsing datetimes from SQLite values. Again, unless I'm missing
something, Jiff is forced to allocate into a `String` first. (But Jiff
only really needs a `&[u8]`.)

I found this experience, along with SQLx, to be absolutely mind-numbing.
Just writing out the example code (which I also used for ad hoc testing)
took an incredible amount of time. I spent _way_ more time playing
fucking type tetris with both SQLx and Diesel than I did anything else
_combined_. It's utterly ridiculous. This further solidifies my opinion
that when you publish crates with an obscene amount of inter-connected
traits, the resulting API becomes very difficult to use.

I'm happy to iterate on the implementation and APIs of this crate (and
`jiff-sqlx`) after an initial release. But I very much appreciate
reviews from Diesel and SQLx experts.

I'm going to say that this closes #50 since this I think this, along
with `jiff-sqlx` and `jiff-icu`, gives us a solid foundation to build
upon. We can track more specific integrations in new issues.

Closes #50

Author: BurntSushi

.github/workflows/ci.yml

@@ -141,6 +141,12 @@ jobs:
       run: cargo build --manifest-path ./examples/sqlx-postgres/Cargo.toml
     - name: Run sqlx-sqlite example
       run: cargo run --manifest-path ./examples/sqlx-sqlite/Cargo.toml
+    - name: Build diesel-mysql example
+      run: cargo build --manifest-path ./examples/diesel-mysql/Cargo.toml
+    - name: Build diesel-postgres example
+      run: cargo build --manifest-path ./examples/diesel-postgres/Cargo.toml
+    - name: Run diesel-sqlite example
+      run: cargo build --manifest-path ./examples/diesel-sqlite/Cargo.toml
 
   # Generic testing for most cross targets. Some get special treatment in
   # other jobs.

.gitignore

@@ -1,5 +1,7 @@
 /Cargo.lock
+/examples/**/Cargo.lock
 /target
+/examples/**/target
 /tmp
 /ecma-test262
 /BREADCRUMBS

.vim/coc-settings.json

@@ -1,6 +1,9 @@
 {
   "rust-analyzer.linkedProjects": [
     "bench/Cargo.toml",
+    "examples/diesel-mysql/Cargo.toml",
+    "examples/diesel-postgres/Cargo.toml",
+    "examples/diesel-sqlite/Cargo.toml",
     "examples/sqlx-postgres/Cargo.toml",
     "examples/sqlx-sqlite/Cargo.toml",
     "Cargo.toml"

Cargo.toml

@@ -31,13 +31,20 @@ include = [
 [workspace]
 members = [
   "crates/jiff-cli",
+  "crates/jiff-diesel",
   "crates/jiff-icu",
   "crates/jiff-sqlx",
   "crates/jiff-tzdb",
   "crates/jiff-tzdb-platform",
   "examples/*",
 ]
-exclude = ["examples/sqlx-postgres", "examples/sqlx-sqlite"]
+exclude = [
+  "examples/diesel-mysql",
+  "examples/diesel-postgres",
+  "examples/diesel-sqlite",
+  "examples/sqlx-postgres",
+  "examples/sqlx-sqlite",
+]
 
 # Features are documented in the "Crate features" section of the crate docs:
 # https://docs.rs/jiff/*/#crate-features

crates/jiff-diesel/COPYING

@@ -0,0 +1,3 @@
+This project is dual-licensed under the Unlicense and MIT licenses.
+
+You may use this code under the terms of either license.

crates/jiff-diesel/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "jiff-diesel"
+version = "0.0.1"  #:version
+authors = ["Andrew Gallant <[email protected]>"]
+license = "Unlicense OR MIT"
+homepage = "https://github.com/BurntSushi/jiff/tree/master/crates/jiff-diesel"
+repository = "https://github.com/BurntSushi/jiff"
+documentation = "https://docs.rs/jiff-diesel"
+description = "Integration for Jiff in Diesel."
+categories = ["date-and-time"]
+keywords = ["date", "time", "jiff", "diesel", "zone"]
+workspace = "../.."
+edition = "2021"
+rust-version = "1.70"
+include = ["/*.rs", "COPYING", "LICENSE-MIT", "UNLICENSE"]
+
+[lib]
+name = "jiff_diesel"
+bench = false
+path = "src/lib.rs"
+
+[features]
+default = []
+mysql = ["diesel/mysql"]
+postgres = ["diesel/postgres"]
+sqlite = ["diesel/sqlite"]
+
+[dependencies]
+jiff = { path = "../..", default-features = false }
+diesel = { version = "2.0.0", default-features = false }
+
+[dev-dependencies]
+jiff = { path = "../..", default-features = true }

crates/jiff-diesel/LICENSE-MIT

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Andrew Gallant
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

crates/jiff-diesel/README.md

@@ -0,0 +1,7 @@
+jiff-icu
+========
+WIP
+
+### Documentation
+
+https://docs.rs/jiff-icu

crates/jiff-diesel/UNLICENSE

@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org/>

crates/jiff-diesel/src/lib.rs

@@ -0,0 +1,70 @@
+/*!
+This crate provides integration points for [Jiff](jiff) and [Diesel](diesel).
+
+Examples can be found in the
+[examples directory of the Jiff repository][examples].
+
+# Organization
+
+This crates defines several types that wrap corresponding types in
+Jiff. Each wrapper type provides implementations of traits found in
+Diesel. For most types, these are the [`diesel::deserialize::Queryable`],
+[`diesel::deserialize::FromSql`] and [`diesel::serialize::ToSql`] traits.
+
+The intended workflow is to use these wrapper types within your wire types for
+encoding and decoding data from databases such as PostgreSQL. The wrapper types
+own the logic for encoding and decoding the data in database specific formats.
+
+In order to the minimize the annoyance of wrapper types, the following
+conveniences are afforded:
+
+* A [`ToDiesel`] trait is provided. Several Jiff types implement this trait.
+The trait provides easy conversion to the corresponding wrapper type in this
+crate.
+* A concrete `to_jiff` method is provided on each wrapper type. For example,
+[`Timestamp::to_jiff`]. This method is the reverse of `ToDiesel`. This converts
+from the wrapper type to the corresponding Jiff type.
+* There are `From` trait implementations from the wrapper type to the
+corresponding Jiff type, and vice versa.
+
+# Database support
+
+At present, MySQL, PostgreSQL and SQLite are supported.
+
+# Future
+
+This crate exists because there are generally only three ways to implement
+the necessary traits in Diesel:
+
+1. Make Jiff depend on Diesel, and implement the corresponding traits where
+Jiff's types are defined.
+2. Make Diesel depend on Jiff, and implement the corresponding traits where the
+traits are defined.
+3. Make a crate like this one with types that wrap Jiff's types, and implements
+the corresponding traits for the wrapper types.
+
+This was done because it seems inappropriate for a "lower level" crate like
+Jiff to depend on Diesel. And while it might be appropriate for Diesel to
+optionally depend on Jiff (like it does for [`chrono`] or [`time`]), at time of
+writing, Jiff is still early in its life. It's totally reasonable to wait for
+it to mature. Plus, the thought of three different datetime integrations is,
+admittedly, tough to stomach.
+
+In the future, it may be prudent for this crate to be upstreamed into Diesel
+itself.
+
+[examples]: https://github.com/BurntSushi/jiff/tree/master/examples
+[`chrono`]: https://docs.rs/chrono
+[`time`]: https://docs.rs/time
+*/
+#![deny(missing_docs)]
+
+pub use self::wrappers::{Date, DateTime, Span, Time, Timestamp, ToDiesel};
+
+#[cfg(feature = "mysql")]
+mod mysql;
+#[cfg(feature = "postgres")]
+mod postgres;
+#[cfg(feature = "sqlite")]
+mod sqlite;
+mod wrappers;