Add validation for bad syntactic shape ID

docs/source/1.0/spec/core/idl.rst

@@ -612,6 +612,17 @@ shape IDs inside of strings, and this difference is inconsequential in the
 resolved to a string that contains a fully-qualified shape ID when parsing
 the model.
 
+.. rubric:: Validation
+
+When a syntactic shape ID is found that does not target an actual shape in
+the fully loaded semantic model, an implementation SHOULD emit a DANGER
+:ref:`validation event <validation>` with an ID of `SyntacticShapeIdTarget`.
+This validation brings attention to the broken reference and helps to ensure
+that modelers do not unintentionally use a syntactic shape ID when they should
+have used a string. A DANGER severity is used so that the validation can be
+:ref:`suppressed <suppression-definition>` in the rare cases that the broken
+reference can be ignored.
+
 
 Defining shapes
 ===============

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

@@ -27,13 +27,17 @@
 import software.amazon.smithy.model.node.NullNode;
 import software.amazon.smithy.model.node.ObjectNode;
 import software.amazon.smithy.model.node.StringNode;
+import software.amazon.smithy.model.validation.Severity;
+import software.amazon.smithy.model.validation.ValidationEvent;
 import software.amazon.smithy.utils.Pair;
 
 /**
  * Parses IDL nodes.
  */
 final class IdlNodeParser {
 
+    private static final String SYNTACTIC_SHAPE_ID_TARGET = "SyntacticShapeIdTarget";
+
     private IdlNodeParser() {}
 
     static Node parseNode(IdlModelParser parser) {
@@ -84,7 +88,19 @@ static Node parseNodeTextWithKeywords(IdlModelParser parser, SourceLocation loca
                 // not be able to be resolved until after the entire model is loaded.
                 Pair<StringNode, Consumer<String>> pair = StringNode.createLazyString(text, location);
                 Consumer<String> consumer = pair.right;
-                parser.modelFile.addForwardReference(text, id -> consumer.accept(id.toString()));
+                parser.modelFile.addForwardReference(text, (id, typeFunction) -> {
+                    if (typeFunction.apply(id) == null) {
+                        parser.modelFile.events().add(ValidationEvent.builder()
+                                .id(SYNTACTIC_SHAPE_ID_TARGET)
+                                .severity(Severity.DANGER)
+                                .message(String.format("Syntactic shape ID `%s` does not resolve to a valid shape ID: "
+                                                       + "`%s`. Did you mean to quote this string? Are you missing a "
+                                                       + "model file?", text, id))
+                                .sourceLocation(location)
+                                .build());
+                    }
+                    consumer.accept(id.toString());
+                });
                 return pair.left;
         }
     }

smithy-model/src/test/java/software/amazon/smithy/model/loader/IdlModelLoaderTest.java

@@ -18,8 +18,10 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
 
+import java.util.List;
 import java.util.Optional;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
@@ -31,7 +33,10 @@
 import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.model.traits.DocumentationTrait;
 import software.amazon.smithy.model.traits.StringTrait;
+import software.amazon.smithy.model.validation.Severity;
+import software.amazon.smithy.model.validation.ValidatedResult;
 import software.amazon.smithy.model.validation.ValidatedResultException;
+import software.amazon.smithy.model.validation.ValidationEvent;
 
 public class IdlModelLoaderTest {
     @Test
@@ -131,4 +136,22 @@ public void handlesMultilineDocComments() {
 
         assertThat(docs, equalTo("This is the first line.\nThis is the second line."));
     }
+
+    @Test
+    public void warnsWhenInvalidSyntacticShapeIdIsFound() {
+        ValidatedResult<Model> result = Model.assembler()
+                .addUnparsedModel("foo.smithy", "namespace smithy.example\n"
+                                                + "@tags([nonono])\n"
+                                                + "string Foo\n")
+                .assemble();
+
+        assertThat(result.isBroken(), is(true));
+        List<ValidationEvent> events = result.getValidationEvents(Severity.DANGER);
+        assertThat(events.stream().filter(e -> e.getId().equals("SyntacticShapeIdTarget")).count(), equalTo(1L));
+        assertThat(events.stream()
+                           .filter(e -> e.getId().equals("SyntacticShapeIdTarget"))
+                           .filter(e -> e.getMessage().contains("`nonono`"))
+                           .count(),
+                   equalTo(1L));
+    }
 }

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/loader/detects-bad-syntactic-shape-ids.errors

@@ -0,0 +1 @@
+[DANGER] -: Syntactic shape ID `GET` does not resolve to a valid shape ID: `smithy.example#GET`. Did you mean to quote this string? Are you missing a model file? | SyntacticShapeIdTarget

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/loader/detects-bad-syntactic-shape-ids.smithy

@@ -0,0 +1,4 @@
+namespace smithy.example
+
+@http(method: GET, uri: "/") // <- Use "GET" not GET!
+operation Foo {}

smithy-model/src/test/resources/software/amazon/smithy/model/knowledge/bottom-up.smithy

@@ -18,7 +18,6 @@ operation Resource1Operation {}
 resource Resource1_2 {}
 
 resource Resource1_1 {
-    type: resource,
     operations: [Resource1_1_Operation],
     resources: [Resource1_1_1, Resource1_1_2]
 }