vpython: Add Python interpreter handling package.

vpython/python/python_test.go

+// Copyright 2017 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package python
+
+import (
+        "fmt"
+        "os"
+        "os/exec"
+        "testing"
+
+        "golang.org/x/net/context"
+
+        . "github.com/luci/luci-go/common/testing/assertions"
+        . "github.com/smartystreets/goconvey/convey"
+)
+
+func TestParsePythonCommandLine(t *testing.T) {
+        t.Parallel()
+
+        successes := []struct {
+                args []string
+                cmd  CommandLine
+        }{
+                {nil, CommandLine{}},
+
+                {[]string{"-a", "-b", "-Q'foo.bar.baz'", "-Wbar"},
+                        CommandLine{
+                                Flags: []string{"-a", "-b", "-Q'foo.bar.baz'", "-Wbar"},
+                                Args:  []string{},
+                        },
+                },
+
+                {[]string{"path.py", "--", "foo", "bar"},
+                        CommandLine{
+                                Type:  TargetScript,
+                                Value: "path.py",
+                                Flags: []string{},
+                                Args:  []string{"--", "foo", "bar"},
+                        },
+                },
+
+                {[]string{"-a", "-Wfoo", "-", "--", "foo"},
+                        CommandLine{
+                                Type:  TargetScript,
+                                Value: "-",
+                                Flags: []string{"-a", "-Wfoo"},
+                                Args:  []string{"--", "foo"},
+                        },
+                },
+
+                {[]string{"-a", "-b", "-W", "foo", "-Wbar", "-c", "<script>", "--", "arg"},
+                        CommandLine{
+                                Type:  TargetCommand,
+                                Value: "<script>",
+                                Flags: []string{"-a", "-b", "-W", "foo", "-Wbar"},
+                                Args:  []string{"--", "arg"},
+                        },
+                },
+
+                {[]string{"-a", "-b", "-m'foo.bar.baz'", "arg"},
+                        CommandLine{
+                                Type:  TargetModule,
+                                Value: "'foo.bar.baz'",
+                                Flags: []string{"-a", "-b"},
+                                Args:  []string{"arg"},
+                        },
+                },
+        }
+
+        failures := []struct {
+                args []string
+                err  string
+        }{
+                {[]string{"-a", "-b", "-Q"}, "truncated two-variable argument"},
+                {[]string{"-c"}, "missing second value"},
+                {[]string{"-\x80"}, "invalid rune in flag"},
+        }
+
+        Convey(`Testing Python command-line parsing`, t, func() {
+                for _, tc := range successes {
+                        Convey(fmt.Sprintf(`Success cases: %v`, tc.args), func() {
+                                cmd, err := ParseCommandLine(tc.args)
+                                So(err, ShouldBeNil)
+                                So(cmd, ShouldResemble, tc.cmd)
+                        })
+                }
+
+                for _, tc := range failures {
+                        Convey(fmt.Sprintf(`Error cases: %v`, tc.args), func() {
+                                _, err := ParseCommandLine(tc.args)
+                                So(err, ShouldErrLike, tc.err)
+                        })
+                }
+        })
+}
+
+func TestInterpreter(t *testing.T) {
+        t.Parallel()
+
+        versionSuccesses := []struct {
+                output string
+                vers   Version
+        }{
+                {"Python 2.7.1\n", Version{2, 7, 1}},
+                {"Python 3", Version{3, 0, 0}},
+        }
+
+        versionFailures := []struct {
+                output string
+                err    string
+        }{
+                {"", "unknown version output"},
+                {"Python2.7.11\n", "unknown version output"},
+                {"Python", "unknown version output"},
+                {"Python 2.7.11 foo bar junk", "invalid number value"},
+                {"Python 3.1.2.3.4", "failed to parse version"},
+        }
+
+        Convey(`A Python interpreter`, t, func() {
+                c := context.Background()
+
+                var (
+                        runnerOutput string
+                        runnerErr    error
+                        lastCmd      *exec.Cmd
+                )
+                i := Interpreter{
+                        testRunner: func(cmd *exec.Cmd, capture bool) (string, error) {
+                                // Sanitize exec.Cmd to exclude its private members for comparison.
+                                lastCmd = &exec.Cmd{
+                                        Path:   cmd.Path,
+                                        Args:   cmd.Args,
+                                        Stdin:  cmd.Stdin,
+                                        Stdout: cmd.Stdout,
+                                        Stderr: cmd.Stderr,
+                                        Env:    cmd.Env,
+                                        Dir:    cmd.Dir,
+                                }
+                                return runnerOutput, runnerErr
+                        },
+                }
+
+                Convey(`Will error if no Python interpreter is supplied.`, func() {
+                        So(i.Command().Run(c, "foo", "bar"), ShouldErrLike, "a Python interpreter must be supplied")
+                })
+
+                Convey(`With a Python interpreter installed`, func() {
+                        i.Python = "/path/to/python"
+
+                        Convey(`Testing Run`, func() {
+                                cmd := i.Command()
+
+                                Convey(`Can run a command.`, func() {
+                                        So(cmd.Run(c, "foo", "bar"), ShouldBeNil)
+                                        So(lastCmd, ShouldResemble, &exec.Cmd{
+                                                Path:   "/path/to/python",
+                                                Args:   []string{"/path/to/python", "foo", "bar"},
+                                                Stdout: os.Stdout,
+                                                Stderr: os.Stderr,
+                                        })
+                                })
+
+                                Convey(`Can run an isolated environment command.`, func() {
+                                        cmd.Isolated = true
+
+                                        So(cmd.Run(c, "foo", "bar"), ShouldBeNil)
+                                        So(lastCmd, ShouldResemble, &exec.Cmd{
+                                                Path:   "/path/to/python",
+                                                Args:   []string{"/path/to/python", "-B", "-E", "-s", "foo", "bar"},
+                                                Stdout: os.Stdout,
+                                                Stderr: os.Stderr,
+                                        })
+                                })
+
+                                Convey(`Can connect STDIN.`, func() {
+                                        cmd.ConnectSTDIN = true
+
+                                        So(cmd.Run(c, "foo", "bar"), ShouldBeNil)
+                                        So(lastCmd, ShouldResemble, &exec.Cmd{
+                                                Path:   "/path/to/python",
+                                                Args:   []string{"/path/to/python", "foo", "bar"},
+                                                Stdout: os.Stdout,
+                                                Stderr: os.Stderr,
+                                                Stdin:  os.Stdin,
+                                        })
+                                })
+
+                                Convey(`Will forward a working directory and enviornment`, func() {
+                                        cmd.WorkDir = "zugzug"
+                                        cmd.Env = []string{"pants=on"}
+
+                                        So(cmd.Run(c, "foo", "bar"), ShouldBeNil)
+                                        So(lastCmd, ShouldResemble, &exec.Cmd{
+                                                Path:   "/path/to/python",
+                                                Args:   []string{"/path/to/python", "foo", "bar"},
+                                                Stdout: os.Stdout,
+                                                Stderr: os.Stderr,
+                                                Env:    []string{"pants=on"},
+                                                Dir:    "zugzug",
+                                        })
+                                })
+                        })
+
+                        Convey(`Testing GetVersion`, func() {
+                                for _, tc := range versionSuccesses {
+                                        Convey(fmt.Sprintf(`Can successfully parse %q => %s`, tc.output, tc.vers), func() {
+                                                runnerOutput = tc.output
+                                                vers, err := i.GetVersion(c)
+                                                So(err, ShouldBeNil)
+                                                So(vers, ShouldResemble, tc.vers)
+                                        })
+                                }
+
+                                for _, tc := range versionFailures {
+                                        Convey(fmt.Sprintf(`Will fail to parse %q (%s)`, tc.output, tc.err), func() {
+                                                runnerOutput = tc.output
+                                                _, err := i.GetVersion(c)
+                                                So(err, ShouldErrLike, tc.err)
+                                        })
+                                }
+                        })
+                })
+        })
+}