Fix smoke test missing params (#2795)

If a smoke test case didn't define input `params`, the validation that
normally checks to make sure `params` matches the operation input would
not run. This meant that you could omit `params` even if the operation
input has required members.

I fixed this by manually checking for required members when `params`
aren't defined (I couldn't use NodeValidationVisitor because it needs an
actual node to check, plus the error message will be better this way).
It emits an error, same as NodeValidationVisitor would.

Also removed a branch in the smoke test input param validation logic, which
would check for cases where `params` were provided for an operation with
no input. This code was unreachable because the method being used to get
the operation's input shape, `OperationIndex::expectInputShape`, always
returns a value, and we were checking for null. There wasn't a test case
for this, so I'm not sure why I wrote it that way to begin with.

Author: milesziemer

smithy-smoke-test-traits/src/main/java/software/amazon/smithy/smoketests/traits/SmokeTestCaseValidator.java

@@ -6,17 +6,19 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import software.amazon.smithy.model.Model;
 import software.amazon.smithy.model.knowledge.OperationIndex;
-import software.amazon.smithy.model.node.Node;
 import software.amazon.smithy.model.node.ObjectNode;
+import software.amazon.smithy.model.shapes.MemberShape;
 import software.amazon.smithy.model.shapes.Shape;
 import software.amazon.smithy.model.shapes.ShapeId;
 import software.amazon.smithy.model.shapes.StructureShape;
 import software.amazon.smithy.model.validation.AbstractValidator;
 import software.amazon.smithy.model.validation.NodeValidationVisitor;
 import software.amazon.smithy.model.validation.ValidationEvent;
+import software.amazon.smithy.model.validation.ValidationUtils;
 import software.amazon.smithy.model.validation.node.TimestampValidationStrategy;
 
 /**
@@ -72,21 +74,29 @@ public List<ValidationEvent> validate(Model model) {
 
                 // Validate input params
                 StructureShape input = operationIndex.expectInputShape(shape);
-                if (input != null && testCase.getParams().isPresent()) {
+                if (testCase.getParams().isPresent()) {
                     NodeValidationVisitor paramsValidator = createVisitor(testCase.getParams().get(),
                             model,
                             shape,
                             testCase.getId(),
                             ".params");
                     events.addAll(input.accept(paramsValidator));
-                } else if (testCase.getParams().isPresent()) {
-                    events.add(error(shape,
-                            trait,
-                            String.format(
-                                    "Smoke test parameters provided for operation with no input: `%s`",
-                                    Node.printJson(testCase.getParams().get())
+                } else {
+                    List<String> requiredMemberNames = new ArrayList<>();
+                    for (Map.Entry<String, MemberShape> entry : input.getAllMembers().entrySet()) {
+                        if (entry.getValue().isRequired()) {
+                            requiredMemberNames.add(entry.getKey());
+                        }
+                    }
 
-                            )));
+                    if (!requiredMemberNames.isEmpty()) {
+                        events.add(error(shape,
+                                trait,
+                                String.format(
+                                        "Smoke test case with ID `%s` does not define `params`, but the target operation has required input members: %s",
+                                        testCase.getId(),
+                                        ValidationUtils.tickedList(requiredMemberNames))));
+                    }
                 }
             }
         }

smithy-smoke-test-traits/src/test/resources/software/amazon/smithy/smoketests/traits/errorfiles/missing-params.errors

@@ -0,0 +1 @@
+[ERROR] smithy.example#Op: Smoke test case with ID `MissingParams` does not define `params`, but the target operation has required input members: `requiredInputMember` | SmokeTestCase

smithy-smoke-test-traits/src/test/resources/software/amazon/smithy/smoketests/traits/errorfiles/missing-params.smithy

@@ -0,0 +1,20 @@
+$version: "2.0"
+
+namespace smithy.example
+
+use smithy.test#smokeTests
+
+@smokeTests([
+    {
+        id: "MissingParams"
+        expect: {
+            failure: {}
+        }
+    }
+])
+operation Op {
+    input := {
+        @required
+        requiredInputMember: String
+    }
+}