From df547d4658c123dc8375cce5f465c4e82f243fa1 Mon Sep 17 00:00:00 2001
From: Dotan Nahum <jondotan@gmail.com>
Date: Thu, 1 Feb 2024 14:04:55 +0200
Subject: [PATCH] feat: migration only #400

---
 src/cli.rs          | 16 +++++++++++++++-
 src/gen/mod.rs      | 15 +++++++++++++--
 src/gen/model.rs    | 41 ++++++++++++++++++++++-------------------
 src/gen/scaffold.rs |  6 ++++--
 4 files changed, 54 insertions(+), 24 deletions(-)

diff --git a/src/cli.rs b/src/cli.rs
index 3d5f8be8f..bcde7213b 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -120,6 +120,10 @@ enum ComponentArg {
         #[arg(short, long, action)]
         link: bool,
 
+        /// Generate migration code only. Don't run the migration automatically.
+        #[arg(short, long, action)]
+        migration_only: bool,
+
         /// Model fields, eg. title:string hits:int
         #[clap(value_parser = parse_key_val::<String,String>)]
         fields: Vec<(String, String)>,
@@ -168,7 +172,17 @@ impl From<ComponentArg> for Component {
     fn from(value: ComponentArg) -> Self {
         match value {
             #[cfg(feature = "with-db")]
-            ComponentArg::Model { name, link, fields } => Self::Model { name, link, fields },
+            ComponentArg::Model {
+                name,
+                link,
+                migration_only,
+                fields,
+            } => Self::Model {
+                name,
+                link,
+                migration_only,
+                fields,
+            },
             #[cfg(feature = "with-db")]
             ComponentArg::Migration { name } => Self::Migration { name },
             #[cfg(feature = "with-db")]
diff --git a/src/gen/mod.rs b/src/gen/mod.rs
index ddc475113..237464c59 100644
--- a/src/gen/mod.rs
+++ b/src/gen/mod.rs
@@ -71,6 +71,9 @@ pub enum Component {
 
         /// Model fields, eg. title:string hits:int
         fields: Vec<(String, String)>,
+
+        /// Generate migration code and stop, don't run the migration
+        migration_only: bool,
     },
     #[cfg(feature = "with-db")]
     Migration {
@@ -109,8 +112,16 @@ pub fn generate<H: Hooks>(component: Component, config: &Config) -> Result<()> {
 
     match component {
         #[cfg(feature = "with-db")]
-        Component::Model { name, link, fields } => {
-            println!("{}", model::generate::<H>(&rrgen, &name, link, &fields)?);
+        Component::Model {
+            name,
+            link,
+            fields,
+            migration_only,
+        } => {
+            println!(
+                "{}",
+                model::generate::<H>(&rrgen, &name, link, migration_only, &fields)?
+            );
         }
         #[cfg(feature = "with-db")]
         Component::Scaffold { name, fields } => {
diff --git a/src/gen/model.rs b/src/gen/model.rs
index 979b97647..54b28b6f3 100644
--- a/src/gen/model.rs
+++ b/src/gen/model.rs
@@ -65,6 +65,7 @@ pub fn generate<H: Hooks>(
     rrgen: &RRgen,
     name: &str,
     is_link: bool,
+    migration_only: bool,
     fields: &[(String, String)],
 ) -> Result<String> {
     let pkg_name: &str = H::app_name();
@@ -101,25 +102,27 @@ pub fn generate<H: Hooks>(
     let res1 = rrgen.generate(MODEL_T, &vars)?;
     let res2 = rrgen.generate(MODEL_TEST_T, &vars)?;
 
-    let cwd = current_dir()?;
-    let _ = cmd!("cargo", "loco", "db", "migrate",)
-        .stderr_to_stdout()
-        .dir(cwd.as_path())
-        .run()
-        .map_err(|err| {
-            Error::Message(format!(
-                "failed to run loco db migration. error details: `{err}`",
-            ))
-        })?;
-    let _ = cmd!("cargo", "loco", "db", "entities",)
-        .stderr_to_stdout()
-        .dir(cwd.as_path())
-        .run()
-        .map_err(|err| {
-            Error::Message(format!(
-                "failed to run loco db entities. error details: `{err}`",
-            ))
-        })?;
+    if !migration_only {
+        let cwd = current_dir()?;
+        let _ = cmd!("cargo", "loco", "db", "migrate",)
+            .stderr_to_stdout()
+            .dir(cwd.as_path())
+            .run()
+            .map_err(|err| {
+                Error::Message(format!(
+                    "failed to run loco db migration. error details: `{err}`",
+                ))
+            })?;
+        let _ = cmd!("cargo", "loco", "db", "entities",)
+            .stderr_to_stdout()
+            .dir(cwd.as_path())
+            .run()
+            .map_err(|err| {
+                Error::Message(format!(
+                    "failed to run loco db entities. error details: `{err}`",
+                ))
+            })?;
+    }
 
     let messages = collect_messages(vec![res1, res2]);
     Ok(messages)
diff --git a/src/gen/scaffold.rs b/src/gen/scaffold.rs
index fd83218c0..3672918fd 100644
--- a/src/gen/scaffold.rs
+++ b/src/gen/scaffold.rs
@@ -37,8 +37,10 @@ pub fn generate<H: Hooks>(
     name: &str,
     fields: &[(String, String)],
 ) -> Result<String> {
-    // scaffold is never a link table
-    let model_messages = model::generate::<H>(rrgen, name, false, fields)?;
+    // - scaffold is never a link table
+    // - never run with migration_only, because the controllers will refer to the
+    //   models. the models only arrive after migration and entities sync.
+    let model_messages = model::generate::<H>(rrgen, name, false, false, fields)?;
 
     let mut columns = Vec::new();
     for (fname, ftype) in fields {