Initial commit

Signed-off-by: jolheiser <john.olheiser@gmail.com>

.gitignore

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+.idea/
+/playground*

LICENSE

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+MIT License
+
+Copyright (c) 2021 John Olheiser
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# go-playground
+
+A library for interacting with the [Go playground](https://play.golang.org).
+
+This library only supports the `share` endpoint of the playground.
+
+If you want to format your code, use `go fmt`.
+
+If you want to evaluate some code, consider using [yaegi](https://github.com/traefik/yaegi).
+
+## Installation
+
+`go install git.jojodev.com/golang/go-playground/cmd/playground@main`
+
+## License
+
+[MIT](LICENSE)

cmd/playground/main.go

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+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	"git.jojodev.com/golang/go-playground"
+)
+
+func main() {
+	contents, err := readStdin()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	if contents == "" {
+		contents, err = readFile()
+		if err != nil {
+			fmt.Println(err)
+			return
+		}
+	}
+
+	if contents == "" {
+		fmt.Println("did not receive any data from stdin or a file")
+		return
+	}
+
+	code, err := playground.Share(context.Background(), contents)
+	if err != nil {
+		fmt.Printf("could not get share URL: %v\n", err)
+		return
+	}
+
+	fmt.Println(code.URL())
+}
+
+func readStdin() (string, error) {
+	fi, err := os.Stdin.Stat()
+	if err != nil {
+		return "", fmt.Errorf("could not stat stdin: %v", err)
+	}
+
+	if fi.Mode()&os.ModeNamedPipe != 0 {
+		contents, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			return "", fmt.Errorf("could not read from stdin: %w", err)
+		}
+		return string(contents), nil
+	}
+	return "", nil
+}
+
+func readFile() (string, error) {
+	if len(os.Args) == 1 {
+		return "", nil
+	}
+
+	path := os.Args[1]
+	fi, err := os.Stat(path)
+	if err != nil {
+		return "", fmt.Errorf("could not stat %s: %v", path, err)
+	}
+	if fi.IsDir() {
+		return "", errors.New("can not share a directory")
+	}
+	if fi.Size() > 500000 {
+		return "", errors.New("this library limits the share payload to ~500kb")
+	}
+
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("could not read file at %s: %w", path, err)
+	}
+
+	return string(contents), nil
+}

go.mod

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+module git.jojodev.com/golang/go-playground
+
+go 1.16

playground.go

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+package playground
+
+import (
+	"context"
+	"crypto/md5"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strings"
+)
+
+var shareURL = "https://play.golang.org/share"
+
+var cache = make(map[string]Code)
+
+// Code is a playground code
+type Code string
+
+func (c Code) URL() string {
+	return fmt.Sprintf("https://play.golang.org/p/%s", c)
+}
+
+// Share creates a share link from text
+func Share(ctx context.Context, contents string) (Code, error) {
+	return share(ctx, contents)
+}
+
+// ShareFile creates a share link from a file
+func ShareFile(ctx context.Context, path string) (Code, error) {
+	stat, err := os.Stat(path)
+	if err != nil {
+		return "", fmt.Errorf("could not stat file: %w", err)
+	}
+
+	if stat.IsDir() {
+		return "", fmt.Errorf("%s is a directory, not a file", path)
+	}
+
+	if !strings.HasSuffix(stat.Name(), ".go") {
+		return "", fmt.Errorf("%s is not a Go file", path)
+	}
+
+	fi, err := os.Open(path)
+	if err != nil {
+		return "", fmt.Errorf("could not open file: %w", err)
+	}
+	defer fi.Close()
+
+	contents, err := io.ReadAll(fi)
+	if err != nil {
+		return "", fmt.Errorf("could not read file: %w", err)
+	}
+
+	return share(ctx, string(contents))
+}
+
+func share(ctx context.Context, contents string) (Code, error) {
+	hash := fmt.Sprintf("%x", md5.Sum([]byte(contents)))
+	if link, ok := cache[hash]; ok {
+		return link, nil
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, shareURL, strings.NewReader(contents))
+	if err != nil {
+		return "", fmt.Errorf("could not create request: %w", err)
+	}
+	req.Header.Set("User-Agent", "git.jojodev.com/golang/go-playground")
+
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("could not create share link: %w", err)
+	}
+	defer res.Body.Close()
+
+	b, err := io.ReadAll(res.Body)
+	if err != nil {
+		return "", fmt.Errorf("could not read response body: %w", err)
+	}
+
+	cache[hash] = Code(b)
+	return cache[hash], nil
+}

playground_test.go

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+package playground
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestShare(t *testing.T) {
+	var resp string
+	contents := "test"
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		resp += "test-"
+		_, _ = w.Write([]byte(resp))
+	}))
+	shareURL = server.URL
+
+	link, err := Share(context.Background(), contents)
+	if err != nil {
+		t.Log(err)
+		t.FailNow()
+	}
+
+	if !strings.EqualFold(link, resp) {
+		t.Logf("Expected `%s` but got `%s`\n", resp, link)
+		t.FailNow()
+	}
+
+	link2, err := Share(context.Background(), contents)
+	if err != nil {
+		t.Log(err)
+		t.FailNow()
+	}
+
+	if !strings.EqualFold(link2, "test-") {
+		t.Logf("Expected `test-` but got `%s`\n", link2)
+		t.FailNow()
+	}
+}