Attempt of using generics instead of interface{} in component's configuration handling and creation.

assets/docs/configuration/transformations/builtin/jq-full-example.hcl

@@ -0,0 +1,15 @@
+transform {
+  use "jq" {
+    jq_command = <<JQEOT
+{
+    my_app_id: .app_id,
+    my_nested_prop: {
+        playback_rate: .contexts_com_snowplowanalytics_snowplow_media_player_1[0].playbackRate
+    }
+}
+JQEOT
+
+    timeout_sec = 5
+    snowplow_mode = true
+  }
+}

assets/docs/configuration/transformations/builtin/jq-minimal-example.hcl

@@ -0,0 +1,5 @@
+transform {
+  use "jq" {
+    jq_command = "[.]"
+  }
+}

assets/test/transformconfig/TestEnginesAndTransformations/configs/transform-mixed-error.hcl

@@ -11,10 +11,3 @@ transform {
     script_path = env.JS_ERROR_PATH
   }
 }
-
-transform {
-  use "lua" {
-    timeout_sec = 15
-    script_path = env.LUA_ADD_HELLO_PATH
-  }
-}

assets/test/transformconfig/TestEnginesAndTransformations/configs/transform-mixed.hcl

@@ -9,9 +9,3 @@ transform {
     script_path = env.JS_ALTER_AID_2_PATH
   }
 }
-
-transform {
-  use "lua" {
-    script_path = env.LUA_ADD_HELLO_PATH
-  }
-}

assets/test/transformconfig/TestGetTransformations/configs/jq.hcl

@@ -0,0 +1,11 @@
+transform {
+  use "jq" {
+    jq_command = <<JQEOT
+{
+    my_app_id: .app_id,
+}
+JQEOT
+
+    snowplow_mode = true
+  }
+}

config/generic/component.go

@@ -0,0 +1,45 @@
+package generic
+
+import (
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/gohcl"
+)
+
+// Implemented by each component, like kinesis target
+type configurableComponent[CONFIG any, COMPONENT any] interface {
+	DefaultConfig() *CONFIG
+	FromConfig(config *CONFIG) (*COMPONENT, error)
+}
+
+// Also implemented by each component, but generic type parameter 'OUT' specifies interface requested by consumer, e.g. 'Target' interface.
+type providerOf[OUT any] interface {
+	Provide(input hcl.Body, ctx *hcl.EvalContext) (OUT, error)
+}
+
+func createComponent[CONFIG any, COMPONENT any](component configurableComponent[CONFIG, COMPONENT], input hcl.Body, ctx *hcl.EvalContext) (*COMPONENT, error) {
+	config := component.DefaultConfig()
+	decode[CONFIG](input, ctx, config)
+	readyComponent, err := component.FromConfig(config)
+
+	if err != nil {
+		return nil, err
+	}
+	return readyComponent, nil
+}
+
+func decode[CONFIG any](input hcl.Body, evalContext *hcl.EvalContext, configuration *CONFIG) error {
+	if input == nil {
+		return nil
+	}
+
+	if configuration == nil {
+		return nil
+	}
+
+	diag := gohcl.DecodeBody(input, evalContext, configuration)
+	if len(diag) > 0 {
+		return diag
+	}
+
+	return nil
+}

config/generic/component_test.go

@@ -0,0 +1,26 @@
+package generic
+
+import (
+	"testing"
+
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclparse"
+	"github.com/stretchr/testify/assert"
+)
+
+var supportedTargets = map[string]providerOf[target]{
+	"testTarget": &testProvider{},
+}
+
+func Test_CreatingTarget(t *testing.T) {
+	assert := assert.New(t)
+	hclFile, _ := hclparse.NewParser().ParseHCL([]byte(`test_string = "ateststring"`), "placeholder.hcl")
+	input := hclFile.Body
+
+	target, _ := supportedTargets["testTarget"].Provide(input, &hcl.EvalContext{})
+
+	output := target.Write("Test string")
+
+	assert.Equal("Written: Test string. This is value in config - ateststring", output)
+
+}

config/generic/example_component.go

@@ -0,0 +1,34 @@
+package generic
+
+import (
+	"github.com/hashicorp/hcl/v2"
+)
+
+type myComponentConfig struct {
+	Test string `hcl:"test_string"`
+}
+
+type myComponent struct {
+	config myComponentConfig
+}
+
+// This one is used by component's clients. If you want ot use component, just use this struct
+type testProvider struct{}
+
+// Return component as interface, here as 'Target'
+func (tp testProvider) Provide(input hcl.Body, ctx *hcl.EvalContext) (target, error) {
+	return createComponent[myComponentConfig, myComponent](tp, input, ctx)
+}
+
+func (testProvider) DefaultConfig() *myComponentConfig {
+	return &myComponentConfig{"some default value"}
+}
+
+func (testProvider) FromConfig(config *myComponentConfig) (*myComponent, error) {
+	return &myComponent{*config}, nil
+}
+
+// Implementing desired interfaces, like 'Target'
+func (mc myComponent) Write(input string) string {
+	return "Written: " + input + ". This is value in config - " + mc.config.Test
+}

config/generic/target.go

@@ -0,0 +1,5 @@
+package generic
+
+type target interface {
+	Write(input string) string
+}

docs/configuration_transformations_docs_test.go

@@ -65,18 +65,12 @@ func TestScriptTransformationCustomScripts(t *testing.T) {
 	// Set env vars with paths to scripts
 	t.Setenv("JS_SCRIPT_PATH", jsScriptPath)
 
-	luaScriptPath := filepath.Join(assets.AssetsRootDir, "docs", "configuration", "transformations", "custom-scripts", "create-a-script-filter-example.lua")
-	t.Setenv("LUA_SCRIPT_PATH", luaScriptPath)
-
 	jsNonSnowplowScriptPath := filepath.Join(assets.AssetsRootDir, "docs", "configuration", "transformations", "custom-scripts", "examples", "js-non-snowplow-script-example.js")
 	t.Setenv("JS_NON_SNOWPLOW_SCRIPT_PATH", jsNonSnowplowScriptPath)
 
 	jsSnowplowScriptPath := filepath.Join(assets.AssetsRootDir, "docs", "configuration", "transformations", "custom-scripts", "examples", "js-snowplow-script-example.js")
 	t.Setenv("JS_SNOWPLOW_SCRIPT_PATH", jsSnowplowScriptPath)
 
-	luaNonSnowplowScriptPath := filepath.Join(assets.AssetsRootDir, "docs", "configuration", "transformations", "custom-scripts", "examples", "lua-script-example.lua")
-	t.Setenv("LUA_SCRIPT_EXAMPLE_PATH", luaNonSnowplowScriptPath)
-
 	baseDir := filepath.Join(assets.AssetsRootDir, "docs", "configuration", "transformations", "custom-scripts")
 
 	filesInBaseDir, err := ioutil.ReadDir(baseDir)
@@ -109,9 +103,6 @@ func TestScriptTransformationCustomScripts(t *testing.T) {
 		case ".js":
 			// Test that all of our JS snippets compile with the engine, pass smoke test, and successfully create a transformation function
 			testJSScriptCompiles(t, file)
-		case ".lua":
-			// Test that all of our Lua snippets compile with the engine, pass smoke test, and successfully create a transformation function
-			testLuaScriptCompiles(t, file)
 		case ".hcl":
 			isFull := strings.Contains(file, "full-example")
 
@@ -168,8 +159,6 @@ func testTransformationConfig(t *testing.T, filepath string, fullExample bool) {
 			configObject = &transform.GTMSSPreviewConfig{}
 		case "js":
 			configObject = &engine.JSEngineConfig{}
-		case "lua":
-			configObject = &engine.LuaEngineConfig{}
 		default:
 			assert.Fail(fmt.Sprint("Source not recognised: ", use.Name))
 		}
@@ -212,19 +201,3 @@ func testJSScriptCompiles(t *testing.T, scriptPath string) {
 	}
 
 }
-
-func testLuaScriptCompiles(t *testing.T, scriptPath string) {
-	assert := assert.New(t)
-
-	luaConfig := &engine.LuaEngineConfig{
-		ScriptPath: scriptPath,
-		RunTimeout: 5, // This is needed here as we're providing config directly, not using defaults.
-	}
-
-	// LuaConfigFunction validates and smoke tests the function, and only returns valid transformation functions.
-	luaTransformationFunction, err := engine.LuaConfigFunction(luaConfig)
-	assert.NotNil(luaTransformationFunction, scriptPath)
-	if err != nil {
-		t.Fatalf("NewLuaEngine failed with error: %s. Script: %s", err.Error(), string(scriptPath))
-	}
-}

go.mod

@@ -37,8 +37,8 @@ require (
 	github.com/xdg/scram v1.0.5
 	golang.org/x/crypto v0.22.0 // indirect
 	golang.org/x/net v0.24.0 // indirect
-	golang.org/x/oauth2 v0.19.0 // indirect
-	golang.org/x/sys v0.19.0 // indirect
+	golang.org/x/oauth2 v0.19.0
+	golang.org/x/sys v0.20.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	google.golang.org/api v0.172.0 // indirect
 	google.golang.org/genproto v0.0.0-20240401170217-c3f982113cda
@@ -50,12 +50,10 @@ require (
 	github.com/davecgh/go-spew v1.1.1
 	github.com/dop251/goja v0.0.0-20240220182346-e401ed450204
 	github.com/hashicorp/hcl/v2 v2.20.1
+	github.com/itchyny/gojq v0.12.16
 	github.com/json-iterator/go v1.1.12
 	github.com/snowplow/snowplow-golang-tracker/v2 v2.4.1
-	github.com/yuin/gluamapper v0.0.0-20150323120927-d836955830e7
-	github.com/yuin/gopher-lua v1.1.1
 	github.com/zclconf/go-cty v1.14.4
-	layeh.com/gopher-json v0.0.0-20201124131017-552bb3c4c3bf
 )
 
 require (
@@ -91,6 +89,7 @@ require (
 	github.com/hashicorp/go-memdb v1.3.4 // indirect
 	github.com/hashicorp/go-uuid v1.0.3 // indirect
 	github.com/hashicorp/golang-lru v1.0.2 // indirect
+	github.com/itchyny/timefmt-go v0.1.6 // indirect
 	github.com/jcmturner/aescts/v2 v2.0.0 // indirect
 	github.com/jcmturner/dnsutils/v2 v2.0.0 // indirect
 	github.com/jcmturner/gofork v1.7.6 // indirect