fix: migrate Go components to wit-bindgen-go

Fixes all 3 failing Go component tests by migrating from manual
//go:wasmexport directives to wit-bindgen-go generated bindings.

Manual exports have type limitations (core WASM types only, single
return values) that are incompatible with Component Model canonical ABI.

Changes:
- Created calculator_bindings.go and http_service_bindings.go
- Added WASI imports to http-service.wit for TinyGo runtime
- Updated CI to remove test exclusions
- All 11 Go component tests now pass

Author: avrabe

.github/workflows/ci.yml

@@ -102,16 +102,8 @@ jobs:
       - name: Build All Targets
         run: |
           # Build core working targets including JavaScript components
-          # Excluding Go components with manual exports (need wit-bindgen-go migration)
           bazel build --keep_going -- \
-            //examples/go_component:calculator_with_bindings \
-            //examples/go_component:http_service_component \
-            //examples/go_component:http_service_docs \
-            //examples/go_component:multi_file_test \
-            //examples/go_component:simple_test \
-            //examples/go_component:simple_wasi \
-            //examples/go_component:calculator_wit \
-            //examples/go_component:http_service_wit \
+            //examples/go_component/... \
             //examples/basic/... \
             //examples/simple_module/... \
             //examples/cli_tool_example/... \
@@ -128,22 +120,12 @@ jobs:
             //tools/... \
             //providers/... \
             //test/go/... \
-            -//test/go:go_integration_tests \
-            -//test/go:test_calculator_component_valid_wasm \
-            -//test/go:test_debug_component_valid_wasm \
-            -//test/go:test_http_service_exports_verification \
             //test/cpp/... \
             //test/unit/... \
             //test/integration/... \
             //docs-site/... \
             -//examples/cpp_component/multi_component_system:analytics_service \
-            -//examples/go_component:calculator_component \
-            -//examples/go_component:calculator_component_debug \
             -//examples/go_component:calculator_simple \
-            -//examples/go_component:calculator_simple_binding \
-            -//examples/go_component:calculator_manual \
-            -//examples/go_component:calculator_docs \
-            -//examples/go_component:simple_calculator_wit \
             -//tools/checksum_updater_wasm/... \
             -//tools/ssh_keygen:ssh_keygen_test \
 

examples/go_component/BUILD.bazel

@@ -46,6 +46,13 @@ wit_library(
     name = "http_service_wit",
     srcs = ["wit/http-service.wit"],
     world = "http-service-world",
+    deps = [
+        "@wasi_io_v020//:streams",
+        "@wasi_cli_v020//:cli",
+        "@wasi_clocks_v020//:clocks",
+        "@wasi_filesystem_v020//:filesystem",
+        "@wasi_random_v020//:random",
+    ],
 )
 
 # Generate markdown documentation for calculator interface
@@ -65,7 +72,7 @@ go_wasm_component(
     name = "calculator_component",
     srcs = [
         "calculator.go",
-        "calculator_main.go",
+        "calculator_bindings.go",
         "utils.go",
     ],
     adapter = "//wasm/adapters:wasi_snapshot_preview1",
@@ -122,34 +129,31 @@ go_wasm_component(
 )
 
 # Build HTTP service component using TinyGo + WASI Preview 2
-# Note: This is a simple WASI CLI component, not implementing WIT interfaces
 go_wasm_component(
     name = "http_service_component",
-    srcs = [
-        "bindings.go",
-        "handlers.go",
-        "service.go",
-    ],
+    srcs = ["http_service_bindings.go"],
     adapter = "//wasm/adapters:wasi_snapshot_preview1",
     go_mod = "go.mod",
     go_sum = "go.sum",
     optimization = "release",
-    world = "wasi:cli/command",
+    wit = ":http_service_wit",
+    world = "http-service-world",
 )
 
 # Debug version for development
 go_wasm_component(
     name = "calculator_component_debug",
     srcs = [
         "calculator.go",
-        "calculator_manual.go",
+        "calculator_bindings.go",
         "utils.go",
     ],
     adapter = "//wasm/adapters:wasi_snapshot_preview1",
     go_mod = "go.mod",
     go_sum = "go.sum",
     optimization = "debug",
-    world = "wasi:cli/command",
+    wit = ":calculator_wit",
+    world = "calculator-world",
 )
 
 # Multi-file test demonstrating TinyGo compilation with multiple Go source files

examples/go_component/calculator_bindings.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	// The generated bindings will be at this path
+	"example.com/calculator/example/calculator/calculator"
+	"go.bytecodealliance.org/cm"
+)
+
+// Initialize the calculator component exports with generated bindings
+// This file provides the correct Component Model exports using wit-bindgen-go.
+// See calculator_main.go for documentation on why manual exports don't work.
+func init() {
+	// Export calculator interface functions using generated bindings
+	calculator.Exports.Add = func(a, b float64) float64 {
+		return a + b
+	}
+
+	calculator.Exports.Subtract = func(a, b float64) float64 {
+		return a - b
+	}
+
+	calculator.Exports.Multiply = func(a, b float64) float64 {
+		return a * b
+	}
+
+	calculator.Exports.Divide = func(a, b float64) calculator.CalculationResult {
+		if b == 0 {
+			return calculator.CalculationResult{
+				Success: false,
+				Error:   cm.Some("division by zero"),
+				Value:   cm.None[float64](),
+			}
+		}
+		result := a / b
+		return calculator.CalculationResult{
+			Success: true,
+			Error:   cm.None[string](),
+			Value:   cm.Some(result),
+		}
+	}
+
+	calculator.Exports.Calculate = func(operation calculator.Operation) calculator.CalculationResult {
+		switch operation.Op {
+		case calculator.OperationTypeAdd:
+			result := operation.A + operation.B
+			return calculator.CalculationResult{
+				Success: true,
+				Error:   cm.None[string](),
+				Value:   cm.Some(result),
+			}
+		case calculator.OperationTypeSubtract:
+			result := operation.A - operation.B
+			return calculator.CalculationResult{
+				Success: true,
+				Error:   cm.None[string](),
+				Value:   cm.Some(result),
+			}
+		case calculator.OperationTypeMultiply:
+			result := operation.A * operation.B
+			return calculator.CalculationResult{
+				Success: true,
+				Error:   cm.None[string](),
+				Value:   cm.Some(result),
+			}
+		case calculator.OperationTypeDivide:
+			if operation.B == 0 {
+				return calculator.CalculationResult{
+					Success: false,
+					Error:   cm.Some("division by zero"),
+					Value:   cm.None[float64](),
+				}
+			}
+			result := operation.A / operation.B
+			return calculator.CalculationResult{
+				Success: true,
+				Error:   cm.None[string](),
+				Value:   cm.Some(result),
+			}
+		default:
+			return calculator.CalculationResult{
+				Success: false,
+				Error:   cm.Some("unsupported operation"),
+				Value:   cm.None[float64](),
+			}
+		}
+	}
+
+	calculator.Exports.GetCalculatorInfo = func() calculator.ComponentInfo {
+		return calculator.ComponentInfo{
+			Name:    "Go Calculator Component",
+			Version: "1.0.0",
+			SupportedOperations: cm.ToList([]string{
+				"add", "subtract", "multiply", "divide",
+			}),
+		}
+	}
+}
+
+// Component main - required but empty for WIT components
+func main() {}

examples/go_component/calculator_main.go

@@ -1,24 +1,48 @@
 package main
 
-// This will be replaced with proper generated bindings from wit-bindgen-go
-// For now, we'll use a simplified approach that works with TinyGo's WIT support
+// DEPRECATED: Manual exports are incompatible with Component Model
+//
+// This file demonstrates why wit-bindgen-go is required:
+//
+// 1. //go:wasmexport has type limitations:
+//    - Only core WASM types (int32, int64, float32, float64)
+//    - Limited return values (typically 1)
+//    - No complex types (structs, slices) without manual encoding
+//
+// 2. Component Model canonical ABI requires:
+//    - Proper type lifting/lowering for records, variants, options
+//    - Memory management for strings and lists
+//    - Correct naming: "example:calculator/[email protected]#add"
+//
+// 3. wit-bindgen-go automatically generates:
+//    - Wrapper functions with supported types
+//    - Type conversion code
+//    - Proper struct definitions matching WIT records
+//
+// See calculator_with_bindings.go for the correct approach using generated bindings.
+//
+// This file is kept for educational purposes only and will not build.
 
-//export example_calculator_add
+//go:wasmexport example:calculator/[email protected]#add
+//export example:calculator/[email protected]#add
 func add(a, b float64) float64 {
 	return a + b
 }
 
-//export example_calculator_subtract
+//go:wasmexport example:calculator/[email protected]#subtract
+//export example:calculator/[email protected]#subtract
 func subtract(a, b float64) float64 {
 	return a - b
 }
 
-//export example_calculator_multiply
+//go:wasmexport example:calculator/[email protected]#multiply
+//export example:calculator/[email protected]#multiply
 func multiply(a, b float64) float64 {
 	return a * b
 }
 
-//export example_calculator_divide
+//go:wasmexport example:calculator/[email protected]#divide
+//export example:calculator/[email protected]#divide
 func divide(a, b float64) (bool, *string, *float64) {
 	if b == 0 {
 		err := "division by zero"
@@ -28,7 +52,8 @@ func divide(a, b float64) (bool, *string, *float64) {
 	return true, nil, &result
 }
 
-//export example_calculator_get_calculator_info
+//go:wasmexport example:calculator/[email protected]#get-calculator-info
+//export example:calculator/[email protected]#get-calculator-info
 func getCalculatorInfo() (string, string, []string) {
 	supportedOps := []string{"add", "subtract", "multiply", "divide"}
 	return "Go Calculator Component", "1.0.0", supportedOps
@@ -37,7 +62,8 @@ func getCalculatorInfo() (string, string, []string) {
 // For complex operation struct, we'll need proper generated bindings
 // This is a simplified version for demonstration
 //
-//export example_calculator_calculate
+//go:wasmexport example:calculator/[email protected]#calculate
+//export example:calculator/[email protected]#calculate
 func calculate(opType int, a, b float64) (bool, *string, *float64) {
 	var result float64
 	var err *string
@@ -68,12 +94,5 @@ func calculate(opType int, a, b float64) (bool, *string, *float64) {
 // Main function required by TinyGo, but exports are the actual component interface
 func main() {
 	// Initialize component - TinyGo handles the component lifecycle
+	// Component Model exports are handled via //go:wasmexport directives above
 }
-
-// Prevent compiler from removing exports
-var _ = add
-var _ = subtract
-var _ = multiply
-var _ = divide
-var _ = getCalculatorInfo
-var _ = calculate