test: correctly makes all example tests runnable (#2281)

Signed-off-by: Takeshi Yoneda <t.y.mathetake@gmail.com>

Makefile

@@ -187,7 +187,7 @@ golangci_lint_goarch ?= $(shell go env GOARCH)
 
 .PHONY: lint
 lint: $(golangci_lint_path)
-	@GOARCH=$(golangci_lint_goarch) CGO_ENABLED=0 $(golangci_lint_path) run --timeout 5m
+	@GOARCH=$(golangci_lint_goarch) CGO_ENABLED=0 $(golangci_lint_path) run --timeout 5m -E testableexamples
 
 .PHONY: format
 format:

experimental/close_example_test.go

@@ -12,7 +12,7 @@ var ctx context.Context
 func Example_closeNotifier() {
 	closeCh := make(chan struct{})
 	ctx = experimental.WithCloseNotifier(
-		ctx,
+		context.Background(),
 		experimental.CloseNotifyFunc(func(context.Context, uint32) { close(closeCh) }),
 	)
 
@@ -24,4 +24,6 @@ func Example_closeNotifier() {
 	default:
 		// do some more work with the module
 	}
+
+	// Output:
 }

experimental/sysfs/config_example_test.go

@@ -20,6 +20,8 @@ func ExampleAdaptFS() {
 
 	moduleConfig = wazero.NewModuleConfig().
 		WithFSConfig(wazero.NewFSConfig().(sysfs.FSConfig).WithSysFSMount(root, "/"))
+
+	// Output:
 }
 
 // This example shows how to configure a sysfs.DirFS
@@ -28,6 +30,8 @@ func ExampleDirFS() {
 
 	moduleConfig = wazero.NewModuleConfig().
 		WithFSConfig(wazero.NewFSConfig().(sysfs.FSConfig).WithSysFSMount(root, "/"))
+
+	// Output:
 }
 
 // This example shows how to configure a sysfs.ReadFS
@@ -37,4 +41,6 @@ func ExampleReadFS() {
 
 	moduleConfig = wazero.NewModuleConfig().
 		WithFSConfig(wazero.NewFSConfig().(sysfs.FSConfig).WithSysFSMount(readOnly, "/"))
+
+	// Output:
 }

fsconfig_example_test.go

@@ -24,4 +24,6 @@ func Example_fsConfig() {
 	moduleConfig = wazero.NewModuleConfig().
 		// Make "index.html" accessible to the guest as "/index.html".
 		WithFSConfig(wazero.NewFSConfig().WithFSMount(rooted, "/"))
+
+	// Output:
 }

sys/stat_example_test.go

@@ -1,38 +0,0 @@
-package sys_test
-
-import (
-	"io/fs"
-	"math"
-
-	"github.com/tetratelabs/wazero/sys"
-)
-
-var (
-	walltime sys.Walltime
-	info     fs.FileInfo
-	st       sys.Stat_t
-)
-
-// This shows typical conversions to sys.EpochNanos type, for sys.Stat_t fields.
-func Example_epochNanos() {
-	// Convert an adapted fs.File's fs.FileInfo to Mtim.
-	st.Mtim = info.ModTime().UnixNano()
-
-	// Generate a fake Atim using sys.Walltime passed to wazero.ModuleConfig.
-	sec, nsec := walltime()
-	st.Atim = sec*1e9 + int64(nsec)
-}
-
-type fileInfoWithSys struct {
-	fs.FileInfo
-	st sys.Stat_t
-}
-
-func (f *fileInfoWithSys) Sys() any { return &f.st }
-
-// This shows how to return data not defined in fs.FileInfo, notably sys.Inode.
-func Example_inode() {
-	st := sys.NewStat_t(info)
-	st.Ino = math.MaxUint64 // arbitrary non-zero value
-	info = &fileInfoWithSys{info, st}
-}