Refactor extension metadata

src/EFCore.PG/Design/Internal/NpgsqlAnnotationCodeGenerator.cs

@@ -67,7 +67,7 @@ public override MethodCallCodeFragment GenerateFluentApi(IModel model, IAnnotati
             Check.NotNull(model, nameof(model));
             Check.NotNull(annotation, nameof(annotation));
 
-            if (annotation.Name.StartsWith(NpgsqlAnnotationNames.PostgresExtensionPrefix))
+            if (annotation.Name.StartsWith(NpgsqlAnnotationNames.PostgresExtensionPrefix, StringComparison.Ordinal))
             {
                 var extension = new PostgresExtension(model, annotation.Name);
 

src/EFCore.PG/Extensions/NpgsqlModelBuilderExtensions.cs

@@ -147,17 +147,53 @@ public static ModelBuilder ForNpgsqlUseIdentityColumns(
 
         #region Extensions
 
+        /// <summary>
+        /// Registers a PostgreSQL extension in the model.
+        /// </summary>
+        /// <param name="modelBuilder">The model builder in which to define the extension.</param>
+        /// <param name="schema">The schema in which to create the extension.</param>
+        /// <param name="name">The name of the extension to create.</param>
+        /// <param name="version">The version of the extension.</param>
+        /// <returns>
+        /// The updated <see cref="ModelBuilder"/>.
+        /// </returns>
+        /// <remarks>
+        /// See: https://www.postgresql.org/docs/current/external-extensions.html
+        /// </remarks>
+        /// <exception cref="ArgumentNullException"><paramref name="modelBuilder"/></exception>
+        [NotNull]
         public static ModelBuilder HasPostgresExtension(
             [NotNull] this ModelBuilder modelBuilder,
-            [NotNull] string name)
+            [CanBeNull] string schema,
+            [NotNull] string name,
+            [CanBeNull] string version)
         {
             Check.NotNull(modelBuilder, nameof(modelBuilder));
+            Check.NullButNotEmpty(schema, nameof(schema));
             Check.NotEmpty(name, nameof(name));
 
-            modelBuilder.Model.Npgsql().GetOrAddPostgresExtension(name);
+            modelBuilder.Model.Npgsql().GetOrAddPostgresExtension(schema, name, version);
             return modelBuilder;
         }
 
+        /// <summary>
+        /// Registers a PostgreSQL extension in the model.
+        /// </summary>
+        /// <param name="modelBuilder">The model builder in which to define the extension.</param>
+        /// <param name="name">The name of the extension to create.</param>
+        /// <returns>
+        /// The updated <see cref="ModelBuilder"/>.
+        /// </returns>
+        /// <remarks>
+        /// See: https://www.postgresql.org/docs/current/external-extensions.html
+        /// </remarks>
+        /// <exception cref="ArgumentNullException"><paramref name="modelBuilder"/></exception>
+        [NotNull]
+        public static ModelBuilder HasPostgresExtension(
+            [NotNull] this ModelBuilder modelBuilder,
+            [NotNull] string name)
+            => modelBuilder.HasPostgresExtension(null, name, null);
+
         #endregion
 
         #region Enums

src/EFCore.PG/Metadata/INpgsqlModelAnnotations.cs

@@ -14,7 +14,7 @@ public interface INpgsqlModelAnnotations : IRelationalModelAnnotations
 
         [NotNull]
         [ItemNotNull]
-        IReadOnlyList<IPostgresExtension> PostgresExtensions { get; }
+        IReadOnlyList<PostgresExtension> PostgresExtensions { get; }
 
         [NotNull]
         [ItemNotNull]

src/EFCore.PG/Metadata/NpgsqlAlterDatabaseOperationAnnotations.cs

@@ -16,12 +16,12 @@ public class NpgsqlAlterDatabaseOperationAnnotations : RelationalAnnotations
 
         [NotNull]
         [ItemNotNull]
-        public virtual IReadOnlyList<IPostgresExtension> PostgresExtensions
+        public virtual IReadOnlyList<PostgresExtension> PostgresExtensions
             => PostgresExtension.GetPostgresExtensions(Metadata).ToArray();
 
         [NotNull]
         [ItemNotNull]
-        public virtual IReadOnlyList<IPostgresExtension> OldPostgresExtensions
+        public virtual IReadOnlyList<PostgresExtension> OldPostgresExtensions
             => PostgresExtension.GetPostgresExtensions(_oldDatabase).ToArray();
 
         [NotNull]
@@ -48,5 +48,12 @@ public virtual IReadOnlyList<PostgresRange> OldPostgresRanges
         public NpgsqlAlterDatabaseOperationAnnotations([NotNull] AlterDatabaseOperation operation)
             : base(operation)
             => _oldDatabase = operation.OldDatabase;
+
+        [NotNull]
+        public virtual PostgresExtension GetOrAddPostgresExtension(
+            [CanBeNull] string schema,
+            [NotNull] string name,
+            [CanBeNull] string version)
+            => PostgresExtension.GetOrAddPostgresExtension((IMutableAnnotatable)Metadata, schema, name, version);
     }
 }

src/EFCore.PG/Metadata/NpgsqlDatabaseModelAnnotations.cs

@@ -10,7 +10,7 @@ public class NpgsqlDatabaseModelAnnotations : RelationalAnnotations
     {
         [NotNull]
         [ItemNotNull]
-        public virtual IReadOnlyList<IPostgresExtension> PostgresExtensions
+        public virtual IReadOnlyList<PostgresExtension> PostgresExtensions
             => PostgresExtension.GetPostgresExtensions(Metadata).ToArray();
 
         [NotNull]
@@ -25,5 +25,12 @@ public virtual IReadOnlyList<PostgresRange> PostgresRanges
 
         /// <inheritdoc />
         public NpgsqlDatabaseModelAnnotations([NotNull] DatabaseModel model) : base(model) {}
+
+        [NotNull]
+        public virtual PostgresExtension GetOrAddPostgresExtension(
+            [CanBeNull] string schema,
+            [NotNull] string name,
+            [CanBeNull] string version)
+            => PostgresExtension.GetOrAddPostgresExtension((IMutableAnnotatable)Metadata, schema, name, version);
     }
 }

src/EFCore.PG/Metadata/NpgsqlModelAnnotations.cs

@@ -64,10 +64,14 @@ protected virtual bool SetValueGenerationStrategy(NpgsqlValueGenerationStrategy?
 
         #region PostgreSQL Extensions
 
-        public virtual PostgresExtension GetOrAddPostgresExtension([NotNull] string name)
-            => PostgresExtension.GetOrAddPostgresExtension((IMutableModel)Model, name);
+        [NotNull]
+        public virtual PostgresExtension GetOrAddPostgresExtension(
+            [CanBeNull] string schema,
+            [NotNull] string name,
+            [CanBeNull] string version)
+            => PostgresExtension.GetOrAddPostgresExtension((IMutableAnnotatable)Model, schema, name, version);
 
-        public virtual IReadOnlyList<IPostgresExtension> PostgresExtensions
+        public virtual IReadOnlyList<PostgresExtension> PostgresExtensions
             => PostgresExtension.GetPostgresExtensions(Model).ToArray();
 
         #endregion