Fix whitespace handling in mixins

designs/mixins.md

@@ -606,14 +606,14 @@ shape being defined and MUST be marked with the `@mixin` trait.
 
 ```
 simple_shape_statement = simple_type_name ws identifier [mixins]
-list_statement = "list" ws identifier [mixins ws] shape_members
-set_statement = "set" ws identifier [mixins ws] shape_members
-map_statement = "map" ws identifier [mixins ws] shape_members
-structure_statement = "structure" ws identifier [mixins ws] structure_members
-union_statement = "union" ws identifier [mixins ws] union_members
-service_statement = "service" ws identifier [mixins ws] node_object
-operation_statement = "operation" ws identifier [mixins ws] node_object
-resource_statement = "resource" ws identifier [mixins ws] node_object
+list_statement = "list" ws identifier [mixins] ws shape_members
+set_statement = "set" ws identifier [mixins] ws shape_members
+map_statement = "map" ws identifier [mixins] ws shape_members
+structure_statement = "structure" ws identifier [mixins] ws structure_members
+union_statement = "union" ws identifier [mixins] ws union_members
+service_statement = "service" ws identifier [mixins] ws node_object
+operation_statement = "operation" ws identifier [mixins] ws node_object
+resource_statement = "resource" ws identifier [mixins] ws node_object
 mixins = sp "with" ws "[" 1*(ws shape_id) ws "]"
 ```
 

smithy-model/src/main/java/software/amazon/smithy/model/loader/IdlModelParser.java

@@ -453,15 +453,11 @@ private ShapeId parseShapeName() {
     private void parseSimpleShape(ShapeId id, SourceLocation location, AbstractShapeBuilder builder) {
         modelFile.onShape(builder.source(location).id(id));
         parseMixins(id);
-        // Pending docs get cleared by parseMixins. It isn't done here because the
-        // mixin parser needs to consume whitespace that may include doc comments for
-        // the next shape in the model.
     }
 
     // See parseMap for information on why members are parsed before the
     // list/set is registered with the ModelFile.
     private void parseCollection(ShapeId id, SourceLocation location, CollectionShape.Builder builder) {
-        ws();
         builder.id(id).source(location);
         parseMixins(id);
         parseMembers(id, SetUtils.of("member"));
@@ -558,17 +554,13 @@ private void parseStructuredShape(
         // "Member `foo.baz#Foo$Baz` cannot be added to software.amazon.smithy.model.shapes.OperationShape$Builder"
         modelFile.onShape(builder.id(id).source(location));
 
-        ws();
-
         // Parse optional "with" statements to add mixins, but only if it's supported by the version.
         parseMixins(id);
         parseMembers(id, Collections.emptySet());
         clearPendingDocs();
     }
 
     private void parseMixins(ShapeId id) {
-        // This is fine for now, but if we ever add any other keywords that start with
-        // 'w' then we'll need to peek farther.
         sp();
         if (peek() != 'w') {
             return;
@@ -698,7 +690,6 @@ private void parseIdList(Consumer<ShapeId> consumer) {
     }
 
     private void parseServiceStatement(ShapeId id, SourceLocation location) {
-        ws();
         parseMixins(id);
         ws();
         ServiceShape.Builder builder = new ServiceShape.Builder().id(id).source(location);
@@ -729,7 +720,6 @@ private void optionalIdList(ObjectNode node, String name, Consumer<ShapeId> cons
     }
 
     private void parseResourceStatement(ShapeId id, SourceLocation location) {
-        ws();
         parseMixins(id);
         ws();
         ResourceShape.Builder builder = ResourceShape.builder().id(id).source(location);

smithy-model/src/test/java/software/amazon/smithy/model/shapes/ListShapeTest.java

@@ -49,7 +49,7 @@ public void mustNotContainMembersInShapeId() {
 
     @Test
     public void requiresMember() {
-        Assertions.assertThrows(IllegalStateException.class, () -> {
+        Assertions.assertThrows(SourceException.class, () -> {
             ListShape.builder().id("ns.foo#bar").build();
         });
     }

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-bigDecimal.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+bigDecimal MixinBigdecimal
+
+bigDecimal MixedBigdecimal
+    with [MixinBigdecimal]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-bigInteger.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+bigInteger MixinBiginteger
+
+bigInteger MixedBiginteger
+    with [MixinBiginteger]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-blob.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+blob MixinBlob
+
+blob MixedBlob
+    with [MixinBlob]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-boolean.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+boolean MixinBoolean
+
+boolean MixedBoolean
+    with [MixinBoolean]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-byte.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+byte MixinByte
+
+byte MixedByte
+    with [MixinByte]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-document.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+document MixinDocument
+
+document MixedDocument
+    with [MixinDocument]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-double.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+double MixinDouble
+
+double MixedDouble
+    with [MixinDouble]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-float.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+float MixinFloat
+
+float MixedFloat
+    with [MixinFloat]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-integer.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+integer MixinInteger
+
+integer MixedInteger
+    with [MixinInteger]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-list.smithy

@@ -0,0 +1,12 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+list MixedList
+    with [MixinList] {}
+
+@mixin
+list MixinList {
+    member: String
+}

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-long.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+long MixinLong
+
+long MixedLong
+    with [MixinLong]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-map.smithy

@@ -0,0 +1,13 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+map MixedMap
+    with [MixinMap] {}
+
+@mixin
+map MixinMap {
+    key: String
+    value: String
+}

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-resource.smithy

@@ -0,0 +1,10 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+resource MixedResource
+    with [MixinResource] {}
+
+@mixin
+resource MixinResource {}

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-service.smithy

@@ -0,0 +1,10 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+service MixedService
+    with [MixinService] {}
+
+@mixin
+service MixinService {}

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-set.smithy

@@ -0,0 +1,13 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+map MixedMap
+    with [MixinMap] {}
+
+@mixin
+map MixinMap {
+    key: String
+    value: String
+}

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-short.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+short MixinShort
+
+short MixedShort
+    with [MixinShort]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-structure.smithy

@@ -0,0 +1,10 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+structure MixedStructure
+    with [MixinStructure] {}
+
+@mixin
+structure MixinStructure {}

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-timestamp.smithy

@@ -0,0 +1,11 @@
+// Parse error at line 10, column 9 near ` `: Unexpected shape type: with
+$version: "2.0"
+
+namespace smithy.example
+
+@mixin
+timestamp MixinTimestamp
+
+timestamp MixedTimestamp
+    with [MixinTimestamp]
+

smithy-model/src/test/resources/software/amazon/smithy/model/loader/invalid/mixins/with-on-next-line-union.smithy

@@ -0,0 +1,10 @@
+// Parse error at line 7, column 5 near `with`: Expected: '{', but found 'w'
+$version: "2.0"
+
+namespace smithy.example
+
+union MixedUnion
+    with [MixinUnion] {}
+
+@mixin
+union MixinUnion {}