import migrations and don't require diesel_cli for admins (#555)

* import migrations via macro

* panic on database not to the latest migration

* add subcommand to plm

* create migration that run tantivy index creation

* remove diesel_cli from places it was

* use our migration system for tests

* create table __diesel_schema_migrations if needed

plume-macro/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "plume-macro"
+version = "0.1.0"
+authors = ["Trinity Pointard <trinity.pointard@insa-rennes.fr>"]
+edition = "2018"
+description = "Plume procedural macros"
+license = "AGPLv3"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "0.4"
+quote = "0.6.12"
+syn = "0.11.4"
+
+
+[features]
+default = []
+postgres = []
+sqlite = []

plume-macro/src/lib.rs

@@ -0,0 +1,139 @@
+#![recursion_limit = "128"]
+extern crate proc_macro;
+#[macro_use]
+extern crate quote;
+extern crate syn;
+
+use proc_macro::TokenStream;
+use proc_macro2::TokenStream as TokenStream2;
+use std::fs::{read_dir, File};
+use std::io::Read;
+use std::str::FromStr;
+
+#[proc_macro]
+pub fn import_migrations(input: TokenStream) -> TokenStream {
+    assert!(input.is_empty());
+    let migration_dir = if cfg!(feature = "postgres") {
+        "migrations/postgres"
+    } else if cfg!(feature = "sqlite") {
+        "migrations/sqlite"
+    } else {
+        "migrations"
+    };
+    let mut files = read_dir(migration_dir)
+        .unwrap()
+        .map(|dir| dir.unwrap())
+        .filter(|dir| dir.file_type().unwrap().is_dir())
+        .map(|dir| dir.path())
+        .collect::<Vec<_>>();
+    files.sort_unstable();
+    let migrations = files
+        .into_iter()
+        .map(|path| {
+            let mut up = path.clone();
+            let mut down = path.clone();
+            up.push("up.sql");
+            down.push("down.sql");
+            let mut up_sql = String::new();
+            let mut down_sql = String::new();
+            File::open(up).unwrap().read_to_string(&mut up_sql).unwrap();
+            File::open(down)
+                .unwrap()
+                .read_to_string(&mut down_sql)
+                .unwrap();
+            let name = path
+                .file_name()
+                .unwrap()
+                .to_str()
+                .unwrap()
+                .chars()
+                .filter(char::is_ascii_digit)
+                .take(14)
+                .collect::<String>();
+            (name, up_sql, down_sql)
+        })
+        .collect::<Vec<_>>();
+    let migrations_name = migrations.iter().map(|m| &m.0).collect::<Vec<_>>();
+    let migrations_up = migrations
+        .iter()
+        .map(|m| m.1.as_str())
+        .map(file_to_migration)
+        .collect::<Vec<_>>();
+    let migrations_down = migrations
+        .iter()
+        .map(|m| m.2.as_str())
+        .map(file_to_migration)
+        .collect::<Vec<_>>();
+
+    /*
+    enum Action {
+        Sql(&'static str),
+        Function(&'static Fn(&Connection, &Path) -> Result<()>)
+    }*/
+
+    quote!(
+        ImportedMigrations(
+            &[#(ComplexMigration{name: #migrations_name, up: #migrations_up, down: #migrations_down}),*]
+            )
+    ).into()
+}
+
+fn file_to_migration(file: &str) -> TokenStream2 {
+    let mut sql = true;
+    let mut acc = String::new();
+    let mut actions = vec![];
+    for line in file.lines() {
+        if sql {
+            if line.starts_with("--#!") {
+                if !acc.trim().is_empty() {
+                    actions.push(quote!(Action::Sql(#acc)));
+                }
+                sql = false;
+                acc = line[4..].to_string();
+                acc.push('\n');
+            } else if line.starts_with("--") {
+                continue;
+            } else {
+                acc.push_str(line);
+                acc.push('\n');
+            }
+        } else {
+            if line.starts_with("--#!") {
+                acc.push_str(&line[4..]);
+                acc.push('\n');
+            } else if line.starts_with("--") {
+                continue;
+            } else {
+                let func: TokenStream2 = trampoline(TokenStream::from_str(&acc).unwrap().into());
+                actions.push(quote!(Action::Function(&#func)));
+                sql = true;
+                acc = line.to_string();
+                acc.push('\n');
+            }
+        }
+    }
+    if !acc.trim().is_empty() {
+        if sql {
+            actions.push(quote!(Action::Sql(#acc)));
+        } else {
+            let func: TokenStream2 = trampoline(TokenStream::from_str(&acc).unwrap().into());
+            actions.push(quote!(Action::Function(&#func)));
+        }
+    }
+
+    quote!(
+        &[#(#actions),*]
+    )
+}
+
+/// Build a trampoline to allow reference to closure from const context
+fn trampoline(closure: TokenStream2) -> TokenStream2 {
+    quote! {
+        {
+            fn trampoline<'a, 'b>(conn: &'a Connection, path: &'b Path) -> Result<()> {
+                (#closure)(conn, path)
+            }
+            trampoline
+        }
+    }
+}