Default output type is any, better inference for try(...) expressions (#398)

Author: Zaid-Ajaj

pkg/modprovider/tfmodules.go

@@ -208,6 +208,23 @@ func inferExpressionType(expr hcl.Expression) schema.TypeSpec {
 		case "compact":
 			// compact function has return type string[]
 			return arrayType(stringType)
+		case "try":
+			// expressions of format: try(<expr1>, <expr2>, ..., <default>)
+			// we check the last argument to see if it is a string literal or null
+			// if it is, we return a string type
+			if len(functionCall.Args) > 0 {
+				lastArg := functionCall.Args[len(functionCall.Args)-1]
+				switch lastArg := lastArg.(type) {
+				case *hclsyntax.LiteralValueExpr:
+					literalStringOrNull := lastArg.Val.Type().Equals(cty.String) ||
+						lastArg.Val.Type().Equals(cty.DynamicPseudoType)
+					if literalStringOrNull {
+						// try function with a string literal as the last argument
+						// returns a string type
+						return stringType
+					}
+				}
+			}
 		}
 	}
 
@@ -232,7 +249,11 @@ func inferExpressionType(expr hcl.Expression) schema.TypeSpec {
 		return arrayType(stringType)
 	}
 
-	return stringType
+	// default output type is any
+	// language SDKs are very strict when it comes to type schematized
+	// they have to match with the actual type at runtime from terraform
+	// so we use any as a fallback
+	return anyType
 }
 
 // isVariableReference checks if the given expression is a reference to a variable
@@ -495,25 +516,33 @@ func combineInferredModuleSchema(
 
 		// if the output already exists, we need to merge the types
 		existingOutput := inferredSchema.Outputs[name]
-		if output.Ref != "" {
-			existingOutput.Ref = output.Ref
-		}
+
 		if output.Description != "" {
 			existingOutput.Description = output.Description
 		}
 		if output.Secret {
 			existingOutput.Secret = output.Secret
 		}
+
+		if output.Ref != "" {
+			existingOutput.Ref = output.Ref
+			existingOutput.TypeSpec.AdditionalProperties = nil
+			existingOutput.TypeSpec.Items = nil
+			existingOutput.TypeSpec.Type = ""
+		}
 		if output.TypeSpec.Type != "" {
 			existingOutput.TypeSpec.Type = output.TypeSpec.Type
+			existingOutput.TypeSpec.Ref = ""
 		}
 		if output.TypeSpec.Items != nil {
 			existingOutput.TypeSpec.Items = output.TypeSpec.Items
 			existingOutput.TypeSpec.AdditionalProperties = nil
+			existingOutput.TypeSpec.Ref = ""
 		}
 		if output.TypeSpec.AdditionalProperties != nil {
 			existingOutput.TypeSpec.AdditionalProperties = output.TypeSpec.AdditionalProperties
 			existingOutput.TypeSpec.Items = nil
+			existingOutput.TypeSpec.Ref = ""
 		}
 	}
 

tests/acc_test.go

@@ -1767,6 +1767,21 @@ func Test_LocalModule_RelativePath_OpenTofu(t *testing.T) {
 	t.Logf("%s", previewResult.StdErr+previewResult.StdOut)
 }
 
+// verify that pulumi package get-schema works which also verifies that the
+// generated schema is valid and can be used to generate an SDK
+func TestPulumiPackageGetSchema(t *testing.T) {
+	t.Parallel()
+	localProviderBinPath := ensureCompiledProvider(t)
+	loadedSchema := pulumiGetSchema(t, localProviderBinPath, []string{
+		"terraform-module",
+		"terraform-aws-modules/vpc/aws",
+		"5.18.1",
+		"vpc",
+	})
+
+	assert.NotEmpty(t, loadedSchema, "expected schema to be loaded")
+}
+
 // assertTFStateResourceExists checks if a resource exists in the TF state.
 // packageName should be the name of the package used in `pulumi package add`
 // resourceAddress should be the full TF address of the resource, e.g. "module.test-bucket.aws_s3_bucket.this"
@@ -1927,6 +1942,29 @@ func ensureCompiledProvider(t *testing.T) string {
 	return binPath
 }
 
+func pulumiGetSchema(t *testing.T, localProviderBinPath string, args []string) string {
+	t.Helper()
+
+	localPulumi := filepath.Join(getRoot(t), ".pulumi", "bin", "pulumi")
+
+	if _, err := os.Stat(localPulumi); os.IsNotExist(err) {
+		t.Errorf("This test requires a locally pinned Pulumi CLI; run `make prepare_local_workspace` first")
+	}
+
+	cmd := exec.Command(localPulumi, append([]string{"package", "get-schema"}, args...)...)
+
+	path := os.Getenv("PATH")
+	path = fmt.Sprintf("%s:%s", filepath.Dir(localProviderBinPath), path)
+
+	cmd.Env = append(os.Environ(), fmt.Sprintf("PATH=%s", path))
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to run pulumi package get-schema: %v\n%s", err, out)
+	}
+
+	return string(out)
+}
+
 func pulumiConvert(t *testing.T, localProviderBinPath, sourceDir, targetDir, language string, generateOnly bool) {
 	t.Helper()