replay - main_test.go

     1  package main
     2  
     3  import (
     4  	"bufio"
     5  	"bytes"
     6  	"fmt"
     7  	"io"
     8  	"io/fs"
     9  	"net/http"
    10  	"net/http/httptest"
    11  	"os"
    12  	"path/filepath"
    13  	"slices"
    14  	"strings"
    15  	"testing"
    16  	"time"
    17  )
    18  
    19  type mapFS map[string]string
    20  
    21  func (m mapFS) Open(name string) (fs.File, error) {
    22  	if str, ok := m[name]; ok {
    23  		return &fileFS{name: name, data: str, l: len(str)}, nil
    24  	}
    25  
    26  	return nil, fs.ErrNotExist
    27  }
    28  
    29  type fileFS struct {
    30  	name string
    31  	data string
    32  	l    int
    33  }
    34  
    35  func (f *fileFS) Stat() (fs.FileInfo, error) {
    36  	return f, nil
    37  }
    38  
    39  func (f *fileFS) Name() string       { return f.name }
    40  func (f *fileFS) Size() int64        { return int64(f.l) }
    41  func (f *fileFS) Mode() fs.FileMode  { return 0644 }
    42  func (f *fileFS) ModTime() time.Time { return time.Now() }
    43  func (f *fileFS) IsDir() bool        { return false }
    44  func (f *fileFS) Sys() any           { return f }
    45  func (f *fileFS) Close() error       { return nil }
    46  
    47  func (f *fileFS) Read(p []byte) (int, error) {
    48  	if len(f.data) == 0 {
    49  		return 0, io.EOF
    50  	}
    51  
    52  	n := copy(p, f.data)
    53  	f.data = f.data[n:]
    54  
    55  	return n, nil
    56  }
    57  
    58  func TestInject(t *testing.T) {
    59  	fs := mapFS{
    60  		"a.css": "some data",
    61  		"b.js":  "alert(1)",
    62  		"c.ts":  "const a: number = 1; alert(a)",
    63  	}
    64  
    65  	s := httptest.NewServer(newMux(fs, nil))
    66  
    67  	checkResponse(t, s.URL+"/a.css", http.StatusOK, "some data")
    68  	checkResponse(t, s.URL+"/b.js", http.StatusOK, string(injectImport)+"alert(1)")
    69  	checkResponse(t, s.URL+"/c.js", http.StatusOK, string(injectImport)+"const a/*: number*/ = 1; alert(a)")
    70  }
    71  
    72  func checkResponse(t *testing.T, url string, code int, data string) {
    73  	resp, err := http.Get(url)
    74  	if err != nil {
    75  		t.Fatalf("unexpected error (%q): %v", url, err)
    76  	} else if resp.StatusCode != code {
    77  		t.Errorf("expecting (%q) status code %d, got %d", url, code, resp.StatusCode)
    78  	}
    79  
    80  	var sb strings.Builder
    81  
    82  	io.Copy(&sb, resp.Body)
    83  
    84  	if str := sb.String(); str != data {
    85  		t.Errorf("expecting (%q) response %q, got %q", url, data, str)
    86  	}
    87  }
    88  
    89  func TestSSE(t *testing.T) {
    90  	tmp := t.TempDir()
    91  
    92  	w, err := NewWatcher(tmp)
    93  	if err != nil {
    94  		t.Fatalf("unexpected error: %v", err)
    95  	}
    96  
    97  	s := httptest.NewServer(newMux(os.DirFS(tmp), w))
    98  
    99  	resp, err := http.Get(s.URL + "/____")
   100  	if err != nil {
   101  		t.Fatalf("unexpected error: %v", err)
   102  	}
   103  
   104  	ch := make(chan struct{})
   105  
   106  	var lines []string
   107  
   108  	go func() {
   109  		defer close(ch)
   110  		defer resp.Body.Close()
   111  
   112  		b := bufio.NewReader(resp.Body)
   113  
   114  		for len(lines) < 4 {
   115  			line, err := b.ReadBytes('\n')
   116  			if err != nil {
   117  				return
   118  			}
   119  
   120  			line = bytes.TrimSpace(line)
   121  
   122  			if len(line) > 0 {
   123  				lines = append(lines, string(line))
   124  			}
   125  		}
   126  	}()
   127  
   128  	f := filepath.Join(tmp, "myFile")
   129  	g := filepath.Join(tmp, "myFile2")
   130  
   131  	if err := os.WriteFile(f, []byte("data"), 0644); err != nil {
   132  		t.Fatalf("unexpected error: %v", err)
   133  	}
   134  
   135  	if err := os.Rename(f, g); err != nil {
   136  		t.Fatalf("unexpected error: %v", err)
   137  	}
   138  
   139  	if f, err := os.Create(g); err != nil {
   140  		t.Fatalf("unexpected error: %v", err)
   141  	} else if _, err = f.WriteString("DATA"); err != nil {
   142  		t.Fatalf("unexpected error: %v", err)
   143  	} else if err = f.Close(); err != nil {
   144  		t.Fatalf("unexpected error: %v", err)
   145  	}
   146  
   147  	if err := os.Rename(g, f); err != nil {
   148  		t.Fatalf("unexpected error: %v", err)
   149  	}
   150  
   151  	<-ch
   152  
   153  	expected := []string{
   154  		fmt.Sprintf("data: CLOSE_WRITE   %q", f),
   155  		fmt.Sprintf("data: RENAME        %q ← %q", g, f),
   156  		fmt.Sprintf("data: CLOSE_WRITE   %q", g),
   157  		fmt.Sprintf("data: RENAME        %q ← %q", f, g),
   158  	}
   159  
   160  	if !slices.Equal(lines, expected) {
   161  		t.Errorf("expected to read %#v, got %#v", expected, lines)
   162  	}
   163  }
   164