Changes RuntimeConfig to an interface and exposes WithWasmCore2 (#518)

WebAssembly Core Working Draft 1 recently came out. Before that, we had
a toe-hold feature bucked called FinishedFeatures. This replaces
`RuntimeConfig.WithFinishedFeatures` with `RuntimeConfig.WithWasmCore2`.
This also adds `WithWasmCore1` for those who want to lock into 1.0
features as opposed to relying on defaults.

This also fixes some design debt where we hadn't finished migrating
public types that require constructor functions (NewXxx) to interfaces.
By using interfaces, we prevent people from accidentally initializing
key configuration directly (via &Xxx), causing nil field refs. This also
helps prevent confusion about how to use the type (ex pointer or not) as
there's only one way (as an interface).

See https://github.com/tetratelabs/wazero/issues/516

Signed-off-by: Adrian Cole <adrian@tetrate.io>

config_test.go

@@ -14,90 +14,108 @@ import (
 func TestRuntimeConfig(t *testing.T) {
 	tests := []struct {
 		name     string
-		with     func(*RuntimeConfig) *RuntimeConfig
-		expected *RuntimeConfig
+		with     func(RuntimeConfig) RuntimeConfig
+		expected RuntimeConfig
 	}{
 		{
 			name: "WithMemoryLimitPages",
-			with: func(c *RuntimeConfig) *RuntimeConfig {
+			with: func(c RuntimeConfig) RuntimeConfig {
 				return c.WithMemoryLimitPages(1)
 			},
-			expected: &RuntimeConfig{
+			expected: &runtimeConfig{
 				memoryLimitPages: 1,
 			},
 		},
 		{
 			name: "bulk-memory-operations",
-			with: func(c *RuntimeConfig) *RuntimeConfig {
+			with: func(c RuntimeConfig) RuntimeConfig {
 				return c.WithFeatureBulkMemoryOperations(true)
 			},
-			expected: &RuntimeConfig{
+			expected: &runtimeConfig{
 				enabledFeatures: wasm.FeatureBulkMemoryOperations,
 			},
 		},
 		{
 			name: "multi-value",
-			with: func(c *RuntimeConfig) *RuntimeConfig {
+			with: func(c RuntimeConfig) RuntimeConfig {
 				return c.WithFeatureMultiValue(true)
 			},
-			expected: &RuntimeConfig{
+			expected: &runtimeConfig{
 				enabledFeatures: wasm.FeatureMultiValue,
 			},
 		},
 		{
 			name: "mutable-global",
-			with: func(c *RuntimeConfig) *RuntimeConfig {
+			with: func(c RuntimeConfig) RuntimeConfig {
 				return c.WithFeatureMutableGlobal(true)
 			},
-			expected: &RuntimeConfig{
+			expected: &runtimeConfig{
 				enabledFeatures: wasm.FeatureMutableGlobal,
 			},
 		},
 		{
 			name: "nontrapping-float-to-int-conversion",
-			with: func(c *RuntimeConfig) *RuntimeConfig {
+			with: func(c RuntimeConfig) RuntimeConfig {
 				return c.WithFeatureNonTrappingFloatToIntConversion(true)
 			},
-			expected: &RuntimeConfig{
+			expected: &runtimeConfig{
 				enabledFeatures: wasm.FeatureNonTrappingFloatToIntConversion,
 			},
 		},
 		{
 			name: "sign-extension-ops",
-			with: func(c *RuntimeConfig) *RuntimeConfig {
+			with: func(c RuntimeConfig) RuntimeConfig {
 				return c.WithFeatureSignExtensionOps(true)
 			},
-			expected: &RuntimeConfig{
+			expected: &runtimeConfig{
 				enabledFeatures: wasm.FeatureSignExtensionOps,
 			},
 		},
+		{
+			name: "REC-wasm-core-1-20191205",
+			with: func(c RuntimeConfig) RuntimeConfig {
+				return c.WithFeatureSignExtensionOps(true).WithWasmCore1()
+			},
+			expected: &runtimeConfig{
+				enabledFeatures: wasm.Features20191205,
+			},
+		},
+		{
+			name: "WD-wasm-core-2-20220419",
+			with: func(c RuntimeConfig) RuntimeConfig {
+				return c.WithFeatureMutableGlobal(false).WithWasmCore2()
+			},
+			expected: &runtimeConfig{
+				enabledFeatures: wasm.Features20220419,
+			},
+		},
 	}
 	for _, tt := range tests {
 		tc := tt
 
 		t.Run(tc.name, func(t *testing.T) {
-			input := &RuntimeConfig{}
+			input := &runtimeConfig{}
 			rc := tc.with(input)
 			require.Equal(t, tc.expected, rc)
 			// The source wasn't modified
-			require.Equal(t, &RuntimeConfig{}, input)
+			require.Equal(t, &runtimeConfig{}, input)
 		})
 	}
 
 	t.Run("WithMemoryCapacityPages", func(t *testing.T) {
-		c := NewRuntimeConfig()
+		c := NewRuntimeConfig().(*runtimeConfig)
 
 		// Test default returns min
 		require.Equal(t, uint32(1), c.memoryCapacityPages(1, nil))
 
 		// Nil ignored
-		c = c.WithMemoryCapacityPages(nil)
+		c = c.WithMemoryCapacityPages(nil).(*runtimeConfig)
 		require.Equal(t, uint32(1), c.memoryCapacityPages(1, nil))
 
 		// Assign a valid function
 		c = c.WithMemoryCapacityPages(func(minPages uint32, maxPages *uint32) uint32 {
 			return 2
-		})
+		}).(*runtimeConfig)
 		// Returns updated value
 		require.Equal(t, uint32(2), c.memoryCapacityPages(1, nil))
 	})
@@ -108,13 +126,13 @@ func TestRuntimeConfig_FeatureToggle(t *testing.T) {
 		name          string
 		feature       wasm.Features
 		expectDefault bool
-		setFeature    func(*RuntimeConfig, bool) *RuntimeConfig
+		setFeature    func(RuntimeConfig, bool) RuntimeConfig
 	}{
 		{
 			name:          "bulk-memory-operations",
 			feature:       wasm.FeatureBulkMemoryOperations,
 			expectDefault: false,
-			setFeature: func(c *RuntimeConfig, v bool) *RuntimeConfig {
+			setFeature: func(c RuntimeConfig, v bool) RuntimeConfig {
 				return c.WithFeatureBulkMemoryOperations(v)
 			},
 		},
@@ -122,7 +140,7 @@ func TestRuntimeConfig_FeatureToggle(t *testing.T) {
 			name:          "multi-value",
 			feature:       wasm.FeatureMultiValue,
 			expectDefault: false,
-			setFeature: func(c *RuntimeConfig, v bool) *RuntimeConfig {
+			setFeature: func(c RuntimeConfig, v bool) RuntimeConfig {
 				return c.WithFeatureMultiValue(v)
 			},
 		},
@@ -130,7 +148,7 @@ func TestRuntimeConfig_FeatureToggle(t *testing.T) {
 			name:          "mutable-global",
 			feature:       wasm.FeatureMutableGlobal,
 			expectDefault: true,
-			setFeature: func(c *RuntimeConfig, v bool) *RuntimeConfig {
+			setFeature: func(c RuntimeConfig, v bool) RuntimeConfig {
 				return c.WithFeatureMutableGlobal(v)
 			},
 		},
@@ -138,7 +156,7 @@ func TestRuntimeConfig_FeatureToggle(t *testing.T) {
 			name:          "nontrapping-float-to-int-conversion",
 			feature:       wasm.FeatureNonTrappingFloatToIntConversion,
 			expectDefault: false,
-			setFeature: func(c *RuntimeConfig, v bool) *RuntimeConfig {
+			setFeature: func(c RuntimeConfig, v bool) RuntimeConfig {
 				return c.WithFeatureNonTrappingFloatToIntConversion(v)
 			},
 		},
@@ -146,7 +164,7 @@ func TestRuntimeConfig_FeatureToggle(t *testing.T) {
 			name:          "sign-extension-ops",
 			feature:       wasm.FeatureSignExtensionOps,
 			expectDefault: false,
-			setFeature: func(c *RuntimeConfig, v bool) *RuntimeConfig {
+			setFeature: func(c RuntimeConfig, v bool) RuntimeConfig {
 				return c.WithFeatureSignExtensionOps(v)
 			},
 		},
@@ -156,19 +174,19 @@ func TestRuntimeConfig_FeatureToggle(t *testing.T) {
 		tc := tt
 
 		t.Run(tc.name, func(t *testing.T) {
-			c := NewRuntimeConfig()
+			c := NewRuntimeConfig().(*runtimeConfig)
 			require.Equal(t, tc.expectDefault, c.enabledFeatures.Get(tc.feature))
 
 			// Set to false even if it was initially false.
-			c = tc.setFeature(c, false)
+			c = tc.setFeature(c, false).(*runtimeConfig)
 			require.False(t, c.enabledFeatures.Get(tc.feature))
 
 			// Set true makes it true
-			c = tc.setFeature(c, true)
+			c = tc.setFeature(c, true).(*runtimeConfig)
 			require.True(t, c.enabledFeatures.Get(tc.feature))
 
 			// Set false makes it false again
-			c = tc.setFeature(c, false)
+			c = tc.setFeature(c, false).(*runtimeConfig)
 			require.False(t, c.enabledFeatures.Get(tc.feature))
 		})
 	}