psl: decouple datasource loader from builtin connectors

The connectors still come from crates datamodel-core depends on, but now
they could come from anywhere else.

The next step will be moving builtin connectors to their own crate, stop
depending on them in datamodel-core, then moving datamodel-connector
into datamodel-core, and injecting the builtin connectors from the psl
crate. We will then have reached our goal of a psl-core crate that does
not depend on any connector but takes them as input.

libs/datamodel/connectors/dml/src/render/render_datamodel.rs

@@ -1,6 +1,6 @@
 use crate::*;
 use ::datamodel::datamodel_connector::{constraint_names::ConstraintNames, Connector, EmptyDatamodelConnector};
-use ::datamodel::{parser_database as db, common::RelationNames, Datasource};
+use ::datamodel::{common::RelationNames, parser_database as db, Datasource};
 use schema_ast::string_literal;
 use std::fmt::Write;
 

libs/datamodel/core/src/lib.rs

@@ -29,6 +29,9 @@ use parser_database::{ast, ParserDatabase, SourceFile};
 pub mod builtin_connectors {
     pub use mongodb_datamodel_connector::*;
     pub use sql_datamodel_connector::*;
+
+    pub(crate) type ConnectorRegistry = &'static [&'static dyn datamodel_connector::Connector];
+    pub(crate) const BUILTIN_CONNECTORS: ConnectorRegistry = &[POSTGRES, MYSQL, SQLITE, MSSQL, COCKROACH, MONGODB];
 }
 
 pub struct ValidatedSchema {
@@ -59,7 +62,7 @@ pub fn parse_schema_parserdb(file: impl Into<SourceFile>) -> Result<ValidatedSch
 pub fn validate(file: SourceFile) -> ValidatedSchema {
     let mut diagnostics = Diagnostics::new();
     let db = ParserDatabase::new(file, &mut diagnostics);
-    let configuration = validate_configuration(db.ast(), &mut diagnostics);
+    let configuration = validate_configuration(db.ast(), &mut diagnostics, builtin_connectors::BUILTIN_CONNECTORS);
     let datasources = &configuration.datasources;
     let out = validate::validate(db, datasources, configuration.preview_features(), diagnostics);
 
@@ -76,14 +79,18 @@ pub fn validate(file: SourceFile) -> ValidatedSchema {
 pub fn parse_configuration(schema: &str) -> Result<Configuration, diagnostics::Diagnostics> {
     let mut diagnostics = Diagnostics::default();
     let ast = schema_ast::parse_schema(schema, &mut diagnostics);
-    let out = validate_configuration(&ast, &mut diagnostics);
+    let out = validate_configuration(&ast, &mut diagnostics, builtin_connectors::BUILTIN_CONNECTORS);
     diagnostics.to_result().map(|_| out)
 }
 
-fn validate_configuration(schema_ast: &ast::SchemaAst, diagnostics: &mut Diagnostics) -> Configuration {
+fn validate_configuration(
+    schema_ast: &ast::SchemaAst,
+    diagnostics: &mut Diagnostics,
+    connectors: builtin_connectors::ConnectorRegistry,
+) -> Configuration {
     let generators = GeneratorLoader::load_generators_from_ast(schema_ast, diagnostics);
     let preview_features = generators.iter().filter_map(|gen| gen.preview_features).collect();
-    let datasources = DatasourceLoader.load_datasources_from_ast(schema_ast, preview_features, diagnostics);
+    let datasources = DatasourceLoader.load_datasources_from_ast(schema_ast, preview_features, diagnostics, connectors);
 
     Configuration {
         generators,

libs/datamodel/core/src/validate/datasource_loader.rs

@@ -7,9 +7,7 @@ use crate::{
 };
 use datamodel_connector::ReferentialIntegrity;
 use enumflags2::BitFlags;
-use mongodb_datamodel_connector::*;
 use parser_database::{ast::WithDocumentation, coerce, coerce_array, coerce_opt};
-use sql_datamodel_connector::*;
 use std::{borrow::Cow, collections::HashMap};
 
 const PREVIEW_FEATURES_KEY: &str = "previewFeatures";
@@ -29,11 +27,12 @@ impl DatasourceLoader {
         ast_schema: &ast::SchemaAst,
         preview_features: BitFlags<PreviewFeature>,
         diagnostics: &mut Diagnostics,
+        connectors: crate::builtin_connectors::ConnectorRegistry,
     ) -> Vec<Datasource> {
         let mut sources = Vec::new();
 
         for src in ast_schema.sources() {
-            if let Some(source) = self.lift_datasource(src, preview_features, diagnostics) {
+            if let Some(source) = self.lift_datasource(src, preview_features, diagnostics, connectors) {
                 sources.push(source)
             }
         }
@@ -56,6 +55,7 @@ impl DatasourceLoader {
         ast_source: &ast::SourceConfig,
         preview_features: BitFlags<PreviewFeature>,
         diagnostics: &mut Diagnostics,
+        connectors: crate::builtin_connectors::ConnectorRegistry,
     ) -> Option<Datasource> {
         let source_name = &ast_source.name.name;
         let mut args: HashMap<_, _> = ast_source
@@ -134,23 +134,18 @@ impl DatasourceLoader {
         let documentation = ast_source.documentation().map(String::from);
         let referential_integrity = get_referential_integrity(&args, preview_features, ast_source, diagnostics);
 
-        let active_connector: &'static dyn datamodel_connector::Connector = match provider {
-            p if MYSQL.is_provider(p) => MYSQL,
-            p if POSTGRES.is_provider(p) => POSTGRES,
-            p if SQLITE.is_provider(p) => SQLITE,
-            p if MSSQL.is_provider(p) => MSSQL,
-            p if MONGODB.is_provider(p) => MONGODB,
-            p if COCKROACH.is_provider(p) => COCKROACH,
-
-            _ => {
-                diagnostics.push_error(DatamodelError::new_datasource_provider_not_known_error(
-                    provider,
-                    provider_arg.span(),
-                ));
+        let active_connector: &'static dyn datamodel_connector::Connector =
+            match connectors.iter().find(|c| c.is_provider(provider)) {
+                Some(c) => *c,
+                None => {
+                    diagnostics.push_error(DatamodelError::new_datasource_provider_not_known_error(
+                        provider,
+                        provider_arg.span(),
+                    ));
 
-                return None;
-            }
-        };
+                    return None;
+                }
+            };
 
         if let Some(integrity) = referential_integrity {
             if !active_connector