feat(macros): type override annotations for columns

This commit is contained in:
Austin Bonander 2020-06-10 20:02:21 -07:00 committed by Ryan Leckey
parent efc4df3eea
commit eb831382e5
3 changed files with 195 additions and 59 deletions

View file

@ -208,6 +208,15 @@ where
RecordType::Generated => {
let record_name: Type = syn::parse_str("Record").unwrap();
for rust_col in &columns {
if rust_col.type_.is_none() {
return Err(
"columns may not have wildcard overrides in `query!()` or `query_as!()"
.into(),
);
}
}
let record_fields = columns.iter().map(
|&output::RustColumn {
ref ident,

View file

@ -1,17 +1,19 @@
use proc_macro2::{Ident, Span, TokenStream};
use quote::quote;
use quote::{quote, ToTokens};
use syn::Type;
use sqlx_core::describe::Describe;
use sqlx_core::describe::{Column, Describe};
use crate::database::DatabaseExt;
use crate::query::QueryMacroInput;
use std::fmt::{self, Display, Formatter};
use syn::parse::{Parse, ParseStream};
use syn::Token;
pub struct RustColumn {
pub(super) ident: Ident,
pub(super) type_: TokenStream,
pub(super) type_: Option<TokenStream>,
}
struct DisplayColumn<'a> {
@ -20,6 +22,18 @@ struct DisplayColumn<'a> {
name: &'a str,
}
struct ColumnDecl {
ident: Ident,
// TIL Rust still has OOP keywords like `abstract`, `final`, `override` and `virtual` reserved
r#override: Option<ColumnOverride>,
}
enum ColumnOverride {
NonNull,
Wildcard,
Exact(Type),
}
impl Display for DisplayColumn<'_> {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "column #{} ({:?})", self.idx + 1, self.name)
@ -32,58 +46,29 @@ pub fn columns_to_rust<DB: DatabaseExt>(describe: &Describe<DB>) -> crate::Resul
.iter()
.enumerate()
.map(|(i, column)| -> crate::Result<_> {
let name = &*column.name;
let ident = parse_ident(name)?;
// add raw prefix to all identifiers
let decl = ColumnDecl::parse(&column.name)
.map_err(|e| format!("column name {:?} is invalid: {}", column.name, e))?;
let mut type_ = if let Some(type_info) = &column.type_info {
<DB as DatabaseExt>::return_type_for_id(&type_info).map_or_else(
|| {
let message = if let Some(feature_gate) =
<DB as DatabaseExt>::get_feature_gate(&type_info)
{
format!(
"optional feature `{feat}` required for type {ty} of {col}",
ty = &type_info,
feat = feature_gate,
col = DisplayColumn {
idx: i,
name: &*column.name
}
)
} else {
format!(
"unsupported type {ty} of {col}",
ty = type_info,
col = DisplayColumn {
idx: i,
name: &*column.name
}
)
};
syn::Error::new(Span::call_site(), message).to_compile_error()
},
|t| t.parse().unwrap(),
)
} else {
syn::Error::new(
Span::call_site(),
format!(
"database couldn't tell us the type of {col}; \
this can happen for columns that are the result of an expression",
col = DisplayColumn {
idx: i,
name: &*column.name
}
),
)
.to_compile_error()
let type_ = match decl.r#override {
Some(ColumnOverride::Exact(ty)) => Some(ty.to_token_stream()),
Some(ColumnOverride::Wildcard) => None,
Some(ColumnOverride::NonNull) => Some(get_column_type(i, column)),
None => {
let type_ = get_column_type(i, column);
if !column.not_null.unwrap_or(false) {
Some(quote! { Option<#type_> })
} else {
Some(type_)
}
}
};
if !column.not_null.unwrap_or(false) {
type_ = quote! { Option<#type_> };
}
Ok(RustColumn { ident, type_ })
Ok(RustColumn {
ident: decl.ident,
type_,
})
})
.collect::<crate::Result<Vec<_>>>()
}
@ -103,13 +88,15 @@ pub fn quote_query_as<DB: DatabaseExt>(
..
},
)| {
// For "checked" queries, the macro checks these at compile time and using "try_get"
// would also perform pointless runtime checks
if input.checked {
quote!( #ident: row.try_get_unchecked::<#type_, _>(#i).try_unwrap_optional()? )
} else {
quote!( #ident: row.try_get_unchecked(#i)? )
match (input.checked, type_) {
// we guarantee the type is valid so we can skip the runtime check
(true, Some(type_)) => quote! {
#ident: row.try_get_unchecked::<#type_, _>(#i).try_unwrap_optional()?
},
// type was overridden to be a wildcard so we fallback to the runtime check
(true, None) => quote! ( #ident: row.try_get(#i)? ),
// macro is the `_unchecked!()` variant so this will die in decoding if it's wrong
(false, _) => quote!( #ident: row.try_get_unchecked(#i)? ),
}
},
);
@ -128,6 +115,99 @@ pub fn quote_query_as<DB: DatabaseExt>(
}
}
fn get_column_type<DB: DatabaseExt>(i: usize, column: &Column<DB>) -> TokenStream {
if let Some(type_info) = &column.type_info {
<DB as DatabaseExt>::return_type_for_id(&type_info).map_or_else(
|| {
let message =
if let Some(feature_gate) = <DB as DatabaseExt>::get_feature_gate(&type_info) {
format!(
"optional feature `{feat}` required for type {ty} of {col}",
ty = &type_info,
feat = feature_gate,
col = DisplayColumn {
idx: i,
name: &*column.name
}
)
} else {
format!(
"unsupported type {ty} of {col}",
ty = type_info,
col = DisplayColumn {
idx: i,
name: &*column.name
}
)
};
syn::Error::new(Span::call_site(), message).to_compile_error()
},
|t| t.parse().unwrap(),
)
} else {
syn::Error::new(
Span::call_site(),
format!(
"database couldn't tell us the type of {col}; \
this can happen for columns that are the result of an expression",
col = DisplayColumn {
idx: i,
name: &*column.name
}
),
)
.to_compile_error()
}
}
impl ColumnDecl {
fn parse(col_name: &str) -> crate::Result<Self> {
// find the end of the identifier because we want to use our own logic to parse it
// if we tried to feed this into `syn::parse_str()` we might get an un-great error
// for some kinds of invalid identifiers
let (ident, remainder) = if let Some(i) = col_name.find(&[':', '!'][..]) {
let (ident, remainder) = col_name.split_at(i);
(parse_ident(ident)?, remainder)
} else {
(parse_ident(col_name)?, "")
};
Ok(ColumnDecl {
ident,
r#override: if !remainder.is_empty() {
Some(syn::parse_str(remainder)?)
} else {
None
},
})
}
}
impl Parse for ColumnOverride {
fn parse(input: ParseStream) -> syn::Result<Self> {
let lookahead = input.lookahead1();
if lookahead.peek(Token![:]) {
input.parse::<Token![:]>()?;
let ty = Type::parse(input)?;
if let Type::Infer(_) = ty {
Ok(ColumnOverride::Wildcard)
} else {
Ok(ColumnOverride::Exact(ty))
}
} else if lookahead.peek(Token![!]) {
input.parse::<Token![!]>()?;
Ok(ColumnOverride::NonNull)
} else {
Err(lookahead.error())
}
}
}
fn parse_ident(name: &str) -> crate::Result<Ident> {
// workaround for the following issue (it's semi-fixed but still spits out extra diagnostics)
// https://github.com/dtolnay/syn/issues/749#issuecomment-575451318

View file

@ -254,3 +254,50 @@ async fn fetch_is_usable_issue_224() -> anyhow::Result<()> {
Ok(())
}
#[sqlx_macros::test]
async fn test_column_override_not_null() -> anyhow::Result<()> {
let mut conn = new::<Postgres>().await?;
let record = sqlx::query!(r#"select 1 as "id!""#)
.fetch_one(&mut conn)
.await?;
assert_eq!(record.id, 1);
Ok(())
}
#[derive(PartialEq, Eq, Debug, sqlx::Type)]
#[sqlx(transparent)]
struct MyInt4(i32);
#[sqlx_macros::test]
async fn test_column_override_wildcard() -> anyhow::Result<()> {
struct Record {
id: MyInt4,
}
let mut conn = new::<Postgres>().await?;
let record = sqlx::query_as!(Record, r#"select 1 as "id: _""#)
.fetch_one(&mut conn)
.await?;
assert_eq!(record.id, MyInt4(1));
Ok(())
}
#[sqlx_macros::test]
async fn test_column_override_exact() -> anyhow::Result<()> {
let mut conn = new::<Postgres>().await?;
let record = sqlx::query!(r#"select 1 as "id: MyInt4""#)
.fetch_one(&mut conn)
.await?;
assert_eq!(record.id, MyInt4(1));
Ok(())
}