use super::{SchemaId, View};
use crate::NodeItem;
use pg_query::{protobuf::ViewStmt, NodeEnum, NodeRef};
impl NodeItem for View {
type Inner = ViewStmt;
fn id(&self) -> String {
self.id.to_string()
}
fn type_name(&self) -> &'static str {
"view"
}
fn node(&self) -> &NodeEnum {
&self.node
}
fn inner(&self) -> anyhow::Result<&Self::Inner> {
match &self.node {
NodeEnum::ViewStmt(stmt) => Ok(stmt),
_ => anyhow::bail!("not a create view statement"),
}
}
fn revert(&self) -> anyhow::Result<NodeEnum> {
let sql = format!("DROP VIEW {}", self.id);
let parsed = pg_query::parse(&sql)?;
let node = parsed.protobuf.nodes()[0].0;
match node {
NodeRef::DropStmt(stmt) => Ok(NodeEnum::DropStmt(stmt.clone())),
_ => anyhow::bail!("not a drop index statement"),
}
}
}
impl TryFrom<&ViewStmt> for View {
type Error = anyhow::Error;
fn try_from(stmt: &ViewStmt) -> Result<Self, Self::Error> {
let id = get_view_id(stmt);
let node = NodeEnum::ViewStmt(Box::new(stmt.clone()));
Ok(Self { id, node })
}
}
fn get_view_id(stmt: &ViewStmt) -> SchemaId {
assert!(stmt.view.is_some());
stmt.view.as_ref().unwrap().into()
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{Differ, MigrationPlanner};
#[test]
fn view_should_parse() {
let sql = "CREATE VIEW foo AS SELECT 1";
let view: View = sql.parse().unwrap();
assert_eq!(view.id.to_string(), "public.foo");
}
#[test]
fn test_view_migration() {
let sql1 = "CREATE VIEW foo AS SELECT 1";
let sql2 = "CREATE VIEW foo AS SELECT 2";
let old: View = sql1.parse().unwrap();
let new: View = sql2.parse().unwrap();
let diff = old.diff(&new).unwrap().unwrap();
let migrations = diff.plan().unwrap();
assert_eq!(migrations.len(), 2);
assert_eq!(migrations[0], "DROP VIEW public.foo");
assert_eq!(migrations[1], "CREATE VIEW foo AS SELECT 2");
}
}