github.com/k14s/starlark-go@v0.0.0-20200720175618-3a5c849cc368/internal/compile/compile_test.go (about)

     1  package compile_test
     2  
     3  import (
     4  	"bytes"
     5  	"strings"
     6  	"testing"
     7  
     8  	"github.com/k14s/starlark-go/starlark"
     9  )
    10  
    11  // TestSerialization verifies that a serialized program can be loaded,
    12  // deserialized, and executed.
    13  func TestSerialization(t *testing.T) {
    14  	predeclared := starlark.StringDict{
    15  		"x": starlark.String("mur"),
    16  		"n": starlark.MakeInt(2),
    17  	}
    18  	const src = `
    19  def mul(a, b):
    20      return a * b
    21  
    22  y = mul(x, n)
    23  `
    24  	_, oldProg, err := starlark.SourceProgram("mul.star", src, predeclared.Has)
    25  	if err != nil {
    26  		t.Fatal(err)
    27  	}
    28  
    29  	buf := new(bytes.Buffer)
    30  	if err := oldProg.Write(buf); err != nil {
    31  		t.Fatalf("oldProg.WriteTo: %v", err)
    32  	}
    33  
    34  	newProg, err := starlark.CompiledProgram(buf)
    35  	if err != nil {
    36  		t.Fatalf("CompiledProgram: %v", err)
    37  	}
    38  
    39  	thread := new(starlark.Thread)
    40  	globals, err := newProg.Init(thread, predeclared)
    41  	if err != nil {
    42  		t.Fatalf("newProg.Init: %v", err)
    43  	}
    44  	if got, want := globals["y"], starlark.String("murmur"); got != want {
    45  		t.Errorf("Value of global was %s, want %s", got, want)
    46  		t.Logf("globals: %v", globals)
    47  	}
    48  
    49  	// Verify stack frame.
    50  	predeclared["n"] = starlark.None
    51  	_, err = newProg.Init(thread, predeclared)
    52  	evalErr, ok := err.(*starlark.EvalError)
    53  	if !ok {
    54  		t.Fatalf("newProg.Init call returned err %v, want *EvalError", err)
    55  	}
    56  	const want = `Traceback (most recent call last):
    57    mul.star:5:8: in <toplevel>
    58    mul.star:3:14: in mul
    59  Error: unknown binary op: string * NoneType`
    60  	if got := evalErr.Backtrace(); got != want {
    61  		t.Fatalf("got <<%s>>, want <<%s>>", got, want)
    62  	}
    63  }
    64  
    65  func TestGarbage(t *testing.T) {
    66  	const garbage = "This is not a compiled Starlark program."
    67  	_, err := starlark.CompiledProgram(strings.NewReader(garbage))
    68  	if err == nil {
    69  		t.Fatalf("CompiledProgram did not report an error when decoding garbage")
    70  	}
    71  	if !strings.Contains(err.Error(), "not a compiled module") {
    72  		t.Fatalf("CompiledProgram reported the wrong error when decoding garbage: %v", err)
    73  	}
    74  }