feat(cli): handle imports in the migration generator

Previously, `use` statements had to be added manually after generating a
migration. This commit adds a simple solution that scans the file for
top-level `use`s, `struct`s and `const`s so that they are imported
automatically.

In addition to that, this adds some tests to the migration generator and
some useful options to the CLI (--app-name and --output-dir to override
the migration's app name and generator's output directory).

Cargo.toml

@@ -71,6 +71,7 @@ sqlx = { version = "0.8", default-features = false, features = ["macros", "json"
 subtle = "2"
 syn = { version = "2", features = ["full", "extra-traits"] }
 sync_wrapper = "1"
+tempfile = "3"
 thiserror = "2"
 time = "0.3.35"
 tokio = { version = "1.40", features = ["macros", "rt-multi-thread"] }

flareon-cli/Cargo.toml

@@ -21,3 +21,7 @@ prettyplease.workspace = true
 proc-macro2 = { workspace = true, features = ["span-locations"] }
 quote.workspace = true
 syn.workspace = true
+
+[dev-dependencies]
+tempfile.workspace = true
+trybuild.workspace = true

flareon-cli/src/lib.rs

@@ -0,0 +1,2 @@
+pub mod migration_generator;
+mod utils;

flareon-cli/src/main.rs

@@ -7,7 +7,7 @@ use anyhow::Context;
 use clap::{Parser, Subcommand};
 use clap_verbosity_flag::Verbosity;
 
-use crate::migration_generator::make_migrations;
+use crate::migration_generator::{make_migrations, MigrationGeneratorOptions};
 
 #[derive(Debug, Parser)]
 #[command(version, about, long_about = None)]
@@ -20,7 +20,18 @@ struct Cli {
 
 #[derive(Debug, Subcommand)]
 enum Commands {
-    MakeMigrations { path: Option<PathBuf> },
+    MakeMigrations {
+        /// Path to the crate directory to generate migrations for (default:
+        /// current directory)
+        path: Option<PathBuf>,
+        /// Name of the app to use in the migration (default: crate name)
+        #[arg(long)]
+        app_name: Option<String>,
+        /// Directory to write the migrations to (default: migrations/ directory
+        /// in the crate's src/ directory)
+        #[arg(long)]
+        output_dir: Option<PathBuf>,
+    },
 }
 
 fn main() -> anyhow::Result<()> {
@@ -31,9 +42,17 @@ fn main() -> anyhow::Result<()> {
         .init();
 
     match cli.command {
-        Commands::MakeMigrations { path } => {
+        Commands::MakeMigrations {
+            path,
+            app_name,
+            output_dir,
+        } => {
             let path = path.unwrap_or_else(|| PathBuf::from("."));
-            make_migrations(&path).with_context(|| "unable to create migrations")?;
+            let options = MigrationGeneratorOptions {
+                app_name,
+                output_dir,
+            };
+            make_migrations(&path, options).with_context(|| "unable to create migrations")?;
         }
     }