fix(psl): handle named args in ds url env (prisma#4958)

We now correctly propagate warnings from the ds url env and emit a warning for the usage of named arguments in the ds url env function

psl/diagnostics/src/error.rs

@@ -29,6 +29,13 @@ impl DatamodelError {
         )
     }
 
+    pub fn new_named_env_val(span: Span) -> Self {
+        Self::new(
+            "The env function expects a singular, unnamed, string argument.".to_owned(),
+            span,
+        )
+    }
+
     pub fn new_argument_not_found_error(argument_name: &str, span: Span) -> DatamodelError {
         Self::new(format!("Argument \"{argument_name}\" is missing."), span)
     }

psl/diagnostics/src/warning.rs

@@ -44,6 +44,11 @@ impl DatamodelWarning {
         Self::new(message, span)
     }
 
+    pub fn new_named_env_val(span: Span) -> Self {
+        let message = "The env function doesn't expect named arguments".to_owned();
+        Self::new(message, span)
+    }
+
     pub fn new_field_validation(message: &str, model: &str, field: &str, span: Span) -> DatamodelWarning {
         let msg = format!(
             "Warning validating field `{}` in {} `{}`: {}",

psl/psl-core/src/configuration/env_vars.rs

@@ -1,5 +1,6 @@
 use crate::parser_database::{ast, coerce};
-use diagnostics::{DatamodelError, Diagnostics};
+use diagnostics::{DatamodelError, DatamodelWarning, Diagnostics};
+use schema_ast::ast::WithSpan;
 use serde::Serialize;
 
 /// Either an env var or a string literal.
@@ -15,16 +16,8 @@ pub struct StringFromEnvVar {
 impl StringFromEnvVar {
     pub(crate) fn coerce(expr: &ast::Expression, diagnostics: &mut Diagnostics) -> Option<Self> {
         match expr {
-            ast::Expression::Function(name, _, _) if name == "env" => {
-                let mut errs = Diagnostics::new();
-                match EnvFunction::from_ast(expr, &mut errs) {
-                    Some(env_function) => Some(StringFromEnvVar::new_from_env_var(env_function.var_name().to_owned())),
-                    None => {
-                        diagnostics.push_error(errs.errors()[0].clone());
-                        None
-                    }
-                }
-            }
+            ast::Expression::Function(name, _, _) if name == "env" => EnvFunction::from_ast(expr, diagnostics)
+                .map(|env_function| StringFromEnvVar::new_from_env_var(env_function.var_name().to_owned())),
             ast::Expression::StringValue(value, _) => Some(StringFromEnvVar::new_literal(value.clone())),
             _ => {
                 diagnostics.push_error(DatamodelError::new_type_mismatch_error(
@@ -71,6 +64,16 @@ impl EnvFunction {
     fn from_ast(expr: &ast::Expression, diagnostics: &mut Diagnostics) -> Option<EnvFunction> {
         let args = if let ast::Expression::Function(name, args, _) = &expr {
             if name == "env" {
+                args.arguments
+                    .iter()
+                    .filter(|arg| !arg.is_unnamed())
+                    .for_each(|arg| diagnostics.push_warning(DatamodelWarning::new_named_env_val(arg.span())));
+
+                if args.arguments.is_empty() && !args.empty_arguments.is_empty() {
+                    diagnostics.push_error(DatamodelError::new_named_env_val(expr.span()));
+                    return None;
+                }
+
                 args
             } else {
                 diagnostics.push_error(DatamodelError::new_functional_evaluation_error(
@@ -87,7 +90,15 @@ impl EnvFunction {
             return None;
         };
 
-        if args.arguments.len() != 1 {
+        if args.arguments.len() + args.empty_arguments.len() != 1 {
+            diagnostics.push_error(DatamodelError::new_functional_evaluation_error(
+                "Exactly one string parameter must be passed to the env function.",
+                expr.span(),
+            ));
+            return None;
+        }
+
+        if args.trailing_comma.is_some() {
             diagnostics.push_error(DatamodelError::new_functional_evaluation_error(
                 "Exactly one string parameter must be passed to the env function.",
                 expr.span(),

psl/psl/tests/validation/datasource/url_empty_named_arg.prisma

@@ -0,0 +1,11 @@
+datasource testds {
+    provider = "mysql"
+    url      = env(named: )
+}
+
+// error: The env function expects a singular, unnamed, string argument.
+//   -->  schema.prisma:3
+//    | 
+//  2 |     provider = "mysql"
+//  3 |     url      = env(named: )
+//    | 

psl/psl/tests/validation/datasource/url_named_arg.prisma

@@ -0,0 +1,11 @@
+datasource testds {
+    provider = "mysql"
+    url      = env(named: "DATABASE_URL")
+}
+
+// warning: The env function doesn't expect named arguments
+//   -->  schema.prisma:3
+//    | 
+//  2 |     provider = "mysql"
+//  3 |     url      = env(named: "DATABASE_URL")
+//    |