Add data source support for response body arrays (#78)

* intial implementation

* added unit tests

* add documentation

* added changelog

* Update DESIGN.md

Co-authored-by: Brian Flad <[email protected]>

* update to default to set

---------

Co-authored-by: Brian Flad <[email protected]>

Author: austinvalle

.changes/unreleased/ENHANCEMENTS-20231019-120611.yaml

@@ -0,0 +1,5 @@
+kind: ENHANCEMENTS
+body: Added data source support for response body arrays
+time: 2023-10-19T12:06:11.101382-04:00
+custom:
+  Issue: "16"

DESIGN.md

@@ -83,6 +83,79 @@ The response body schema found will be deep merged with the query/path `paramete
   - Names are strictly compared, so `id` and `user_id` would be two separate attributes in a schema.
 - Arrays and Objects will have their child attributes merged, so `example_object.string_field` and `example_object.bool_field` will be merged into the same `SingleNestedAttribute` schema.
 
+#### Collection Data Sources
+
+If the response body schema for a data source is of type `array`, the schema in `items` will be mapped to a set collection attribute (`SetNested` or `Set`) at the root of the mapped data source. The name of the attribute will be the same as the data source name from the generator config. All [mapping rules](#oas-types-to-provider-attributes) will be followed for nested attributes.
+
+##### Generator Config
+```yaml
+provider:
+  name: petstore
+
+data_sources:
+  pets:
+    read:
+      path: /pet/findByStatus
+      method: GET
+```
+
+##### OpenAPI Spec
+```jsonc
+{
+  // ... Rest of OAS
+  "/pet/findByStatus": {
+    "get": {
+      "responses": {
+        "200": {
+          "description": "successful operation",
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "array",
+                "items": {
+                  "$ref": "#/components/schemas/Pet"
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
+```
+
+##### Provider Code Spec output
+```jsonc
+{
+  "datasources": [
+    {
+      "name": "pets",
+      "schema": {
+        "attributes": [
+          {
+            "name": "pets",
+            "set_nested": {
+              "computed_optional_required": "computed",
+              "nested_object": {
+                "attributes": [
+                  // ... mapping of #/components/schemas/Pet
+                ]
+              }
+            }
+          }
+        ]
+      }
+    }
+  ],
+  "provider": {
+    "name": "petstore"
+  }
+}
+```
+
+
+
 ### OAS Types to Provider Attributes
 
 For a given OAS [`type`](https://spec.openapis.org/oas/v3.1.0#data-types) and `format` combination, the following rules will be applied for mapping to the provider code specification. Not all Provider attributes are represented natively with OAS, those types are noted below in [Unsupported Attributes](#unsupported-attributes).

internal/cmd/testdata/petstore3/provider_code_spec.json

@@ -149,6 +149,86 @@
 								}
 							]
 						}
+					},
+					{
+						"name": "pets",
+						"set_nested": {
+							"computed_optional_required": "computed",
+							"nested_object": {
+								"attributes": [
+									{
+										"name": "category",
+										"single_nested": {
+											"computed_optional_required": "computed",
+											"attributes": [
+												{
+													"name": "id",
+													"int64": {
+														"computed_optional_required": "computed"
+													}
+												},
+												{
+													"name": "name",
+													"string": {
+														"computed_optional_required": "computed"
+													}
+												}
+											]
+										}
+									},
+									{
+										"name": "id",
+										"int64": {
+											"computed_optional_required": "computed"
+										}
+									},
+									{
+										"name": "name",
+										"string": {
+											"computed_optional_required": "computed"
+										}
+									},
+									{
+										"name": "photo_urls",
+										"list": {
+											"computed_optional_required": "computed",
+											"element_type": {
+												"string": {}
+											}
+										}
+									},
+									{
+										"name": "status",
+										"string": {
+											"computed_optional_required": "computed",
+											"description": "pet status in the store"
+										}
+									},
+									{
+										"name": "tags",
+										"list_nested": {
+											"computed_optional_required": "computed",
+											"nested_object": {
+												"attributes": [
+													{
+														"name": "id",
+														"int64": {
+															"computed_optional_required": "computed"
+														}
+													},
+													{
+														"name": "name",
+														"string": {
+															"computed_optional_required": "computed"
+														}
+													}
+												]
+											}
+										}
+									}
+								]
+							}
+						}
 					}
 				]
 			}

internal/mapper/datasource_mapper.go

@@ -4,6 +4,7 @@
 package mapper
 
 import (
+	"fmt"
 	"log/slog"
 
 	"github.com/hashicorp/terraform-plugin-codegen-openapi/internal/config"
@@ -44,7 +45,7 @@ func (m dataSourceMapper) MapToIR(logger *slog.Logger) ([]datasource.DataSource,
 		dataSource := m.dataSources[name]
 		dLogger := logger.With("data_source", name)
 
-		schema, err := generateDataSourceSchema(dLogger, dataSource)
+		schema, err := generateDataSourceSchema(dLogger, name, dataSource)
 		if err != nil {
 			log.WarnLogOnError(dLogger, err, "skipping data source schema mapping")
 			continue
@@ -59,7 +60,7 @@ func (m dataSourceMapper) MapToIR(logger *slog.Logger) ([]datasource.DataSource,
 	return dataSourceSchemas, nil
 }
 
-func generateDataSourceSchema(logger *slog.Logger, dataSource explorer.DataSource) (*datasource.Schema, error) {
+func generateDataSourceSchema(logger *slog.Logger, name string, dataSource explorer.DataSource) (*datasource.Schema, error) {
 	dataSourceSchema := &datasource.Schema{
 		Attributes: []datasource.Attribute{},
 	}
@@ -72,9 +73,27 @@ func generateDataSourceSchema(logger *slog.Logger, dataSource explorer.DataSourc
 	if err != nil {
 		return nil, err
 	}
-	readResponseAttributes, schemaErr := readResponseSchema.BuildDataSourceAttributes()
-	if schemaErr != nil {
-		return nil, schemaErr
+
+	readResponseAttributes := attrmapper.DataSourceAttributes{}
+	if readResponseSchema.Type == util.OAS_type_array {
+		logger.Debug(fmt.Sprintf("response body is an array, building '%s' set attribute", name))
+
+		// API's generally don't guarantee ordering of results for collection/query responses, default mapping to set
+		readResponseSchema.Format = util.TF_format_set
+
+		collectionAttribute, schemaErr := readResponseSchema.BuildDataSourceAttribute(name, schema.Computed)
+		if schemaErr != nil {
+			return nil, schemaErr
+		}
+
+		readResponseAttributes = append(readResponseAttributes, collectionAttribute)
+	} else {
+		attributes, schemaErr := readResponseSchema.BuildDataSourceAttributes()
+		if schemaErr != nil {
+			return nil, schemaErr
+		}
+
+		readResponseAttributes = attributes
 	}
 
 	// ****************