wasmserve: bug fix: invalid URL for some Go versions

Author: hajimehoshi

.github/workflows/test.yml

@@ -0,0 +1,27 @@
+name: Test
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        go: ['1.16.x', '1.23.x', '1.24.x']
+    name: Test with Go ${{ matrix.go }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    defaults:
+      run:
+        shell: bash
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Setup Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go }}
+
+    - name: Test
+      run: |
+        go test -v ./...

example/main.go

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2018 Hajime Hoshi
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"syscall/js"
+)
+
+func main() {
+	flag.Parse()
+	fmt.Println(flag.Args())
+
+	p := js.Global().Get("document").Call("createElement", "p")
+	p.Set("innerText", "Hello, World!")
+	js.Global().Get("document").Get("body").Call("appendChild", p)
+
+	pre := js.Global().Get("document").Call("createElement", "pre")
+	pre.Set("innerText", fmt.Sprintf("args: %q\nevn: %q", os.Args, os.Environ()))
+	pre.Get("style").Set("whiteSpace", "pre-wrap")
+	js.Global().Get("document").Get("body").Call("appendChild", pre)
+}

example/main_js.go

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2025 Hajime Hoshi
+
+package wasmserveutil
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+)
+
+var reGoVersion = regexp.MustCompile(`^go(\d+)\.(\d+)(\.(\d+))?`)
+
+func WasmExecJSURL(goVersion string) (string, error) {
+	// go.mod might have a version without `.0` like `go1.22`. This version might not work as a part of URL.
+	m := reGoVersion.FindStringSubmatch(goVersion)
+	if len(m) == 0 {
+		return "", fmt.Errorf("wasmserve: invalid Go version: %s", goVersion)
+	}
+	minor, _ := strconv.Atoi(m[2])
+	if minor >= 22 && m[3] == "" {
+		goVersion += ".0"
+	}
+	dir := "lib"
+	if minor <= 23 {
+		dir = "misc"
+	}
+	return fmt.Sprintf("https://go.googlesource.com/go/+/refs/tags/%s/%s/wasm/wasm_exec.js?format=TEXT", goVersion, dir), nil
+}

internal/wasmserveutil/util.go

@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2025 Hajime Hoshi
+
+package wasmserveutil_test
+
+import (
+	"testing"
+
+	"github.com/hajimehoshi/wasmserve/internal/wasmserveutil"
+)
+
+func TestWasmExecJSURL(t *testing.T) {
+	testCases := []struct {
+		goVersion string
+		url       string
+		error     bool
+	}{
+		{
+			goVersion: "invalid",
+			url:       "",
+			error:     true,
+		},
+		{
+			goVersion: "go1.16",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.16/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.21",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.21/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.22",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.22.0/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.22.0",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.22.0/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.22.1",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.22.1/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.23",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.23.0/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.23.0",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.23.0/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.23.1",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.23.1/misc/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.24",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.24.0/lib/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.24.0",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.24.0/lib/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+		{
+			goVersion: "go1.24.1",
+			url:       "https://go.googlesource.com/go/+/refs/tags/go1.24.1/lib/wasm/wasm_exec.js?format=TEXT",
+			error:     false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.goVersion, func(t *testing.T) {
+			url, err := wasmserveutil.WasmExecJSURL(tc.goVersion)
+			if err != nil && !tc.error {
+				t.Errorf("unexpected error: %v", err)
+				return
+			}
+			if err == nil && tc.error {
+				t.Errorf("no error")
+				return
+			}
+			if url != tc.url {
+				t.Errorf("got: %s, want: %s", url, tc.url)
+			}
+		})
+	}
+}

internal/wasmserveutil/util_test.go

@@ -1,16 +1,5 @@
-// Copyright 2018 Hajime Hoshi
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2018 Hajime Hoshi
 
 package main
 
@@ -33,6 +22,8 @@ import (
 	"strings"
 	"text/template"
 	"time"
+
+	"github.com/hajimehoshi/wasmserve/internal/wasmserveutil"
 )
 
 const mainWasm = "main.wasm"
@@ -335,9 +326,12 @@ func fetchWasmExecJS() ([]byte, error) {
 		return nil, err
 	}
 
-	// TODO: Cache the result.
+	url, err := wasmserveutil.WasmExecJSURL(v)
+	if err != nil {
+		return nil, err
+	}
 
-	url := fmt.Sprintf("https://go.googlesource.com/go/+/refs/tags/%s/misc/wasm/wasm_exec.js?format=TEXT", v)
+	// TODO: Cache the result.
 	resp, err := http.Get(url)
 	if err != nil {
 		return nil, err