github.com/lab47/exprcore@v0.0.0-20210525052339-fb7d6bd9331e/exprcore/profile_test.go (about)

     1  // Copyright 2019 The Bazel Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package exprcore_test
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"io/ioutil"
    11  	"os"
    12  	"os/exec"
    13  	"strings"
    14  	"testing"
    15  
    16  	"github.com/lab47/exprcore/exprcore"
    17  )
    18  
    19  // TestProfile is a simple integration test that the profiler
    20  // emits minimally plausible pprof-compatible output.
    21  func TestProfile(t *testing.T) {
    22  	prof, err := ioutil.TempFile("", "profile_test")
    23  	if err != nil {
    24  		t.Fatal(err)
    25  	}
    26  	defer prof.Close()
    27  	defer os.Remove(prof.Name())
    28  	if err := exprcore.StartProfile(prof); err != nil {
    29  		t.Fatal(err)
    30  	}
    31  
    32  	const src = `
    33  def fibonacci(n) {
    34  	res = list(range(n))
    35  	for i in res[2:] {
    36  		res[i] = res[i-2] + res[i-1]
    37  	}
    38  	return res
    39  }
    40  fibonacci(100000)
    41  `
    42  
    43  	thread := new(exprcore.Thread)
    44  	if _, err := exprcore.ExecFile(thread, "foo.star", src, nil); err != nil {
    45  		_ = exprcore.StopProfile()
    46  		t.Fatal(err)
    47  	}
    48  	if err := exprcore.StopProfile(); err != nil {
    49  		t.Fatal(err)
    50  	}
    51  	prof.Sync()
    52  	cmd := exec.Command("go", "tool", "pprof", "-top", prof.Name())
    53  	cmd.Stderr = new(bytes.Buffer)
    54  	cmd.Stdout = new(bytes.Buffer)
    55  	if err := cmd.Run(); err != nil {
    56  		t.Fatalf("pprof failed: %v; output=<<%s>>", err, cmd.Stderr)
    57  	}
    58  
    59  	// Typical output (may vary by go release):
    60  	//
    61  	// Type: wall
    62  	// Time: Apr 4, 2019 at 11:10am (EDT)
    63  	// Duration: 251.62ms, Total samples = 250ms (99.36%)
    64  	// Showing nodes accounting for 250ms, 100% of 250ms total
    65  	//  flat  flat%   sum%        cum   cum%
    66  	// 320ms   100%   100%      320ms   100%  fibonacci
    67  	//     0     0%   100%      320ms   100%  foo.star
    68  	//
    69  	// We'll assert a few key substrings are present.
    70  	got := fmt.Sprint(cmd.Stdout)
    71  	for _, want := range []string{
    72  		"flat%",
    73  		"fibonacci",
    74  		"foo.star",
    75  	} {
    76  		if !strings.Contains(got, want) {
    77  			t.Errorf("output did not contain %q", want)
    78  		}
    79  	}
    80  	if t.Failed() {
    81  		t.Logf("stderr=%v", cmd.Stderr)
    82  		t.Logf("stdout=%v", cmd.Stdout)
    83  	}
    84  }