github.com/i0n/terraform@v0.4.3-0.20150506151324-010a39a58ec1/state/testing.go (about)

     1  package state
     2  
     3  import (
     4  	"bytes"
     5  	"reflect"
     6  	"testing"
     7  
     8  	"github.com/hashicorp/terraform/terraform"
     9  )
    10  
    11  // TestState is a helper for testing state implementations. It is expected
    12  // that the given implementation is pre-loaded with the TestStateInitial
    13  // state.
    14  func TestState(t *testing.T, s interface{}) {
    15  	reader, ok := s.(StateReader)
    16  	if !ok {
    17  		t.Fatalf("must at least be a StateReader")
    18  	}
    19  
    20  	// If it implements refresh, refresh
    21  	if rs, ok := s.(StateRefresher); ok {
    22  		if err := rs.RefreshState(); err != nil {
    23  			t.Fatalf("err: %s", err)
    24  		}
    25  	}
    26  
    27  	// current will track our current state
    28  	current := TestStateInitial()
    29  
    30  	// Check that the initial state is correct
    31  	if state := reader.State(); !current.Equal(state) {
    32  		t.Fatalf("not initial: %#v\n\n%#v", state, current)
    33  	}
    34  
    35  	// Write a new state and verify that we have it
    36  	if ws, ok := s.(StateWriter); ok {
    37  		current.Modules = append(current.Modules, &terraform.ModuleState{
    38  			Path: []string{"root"},
    39  			Outputs: map[string]string{
    40  				"bar": "baz",
    41  			},
    42  		})
    43  
    44  		if err := ws.WriteState(current); err != nil {
    45  			t.Fatalf("err: %s", err)
    46  		}
    47  
    48  		if actual := reader.State(); !actual.Equal(current) {
    49  			t.Fatalf("bad: %#v\n\n%#v", actual, current)
    50  		}
    51  	}
    52  
    53  	// Test persistence
    54  	if ps, ok := s.(StatePersister); ok {
    55  		if err := ps.PersistState(); err != nil {
    56  			t.Fatalf("err: %s", err)
    57  		}
    58  
    59  		// Refresh if we got it
    60  		if rs, ok := s.(StateRefresher); ok {
    61  			if err := rs.RefreshState(); err != nil {
    62  				t.Fatalf("err: %s", err)
    63  			}
    64  		}
    65  
    66  		// Just set the serials the same... Then compare.
    67  		actual := reader.State()
    68  		if !actual.Equal(current) {
    69  			t.Fatalf("bad: %#v\n\n%#v", actual, current)
    70  		}
    71  	}
    72  
    73  	// If we can write and persist then verify that the serial
    74  	// is only implemented on change.
    75  	writer, writeOk := s.(StateWriter)
    76  	persister, persistOk := s.(StatePersister)
    77  	if writeOk && persistOk {
    78  		// Same serial
    79  		serial := current.Serial
    80  		if err := writer.WriteState(current); err != nil {
    81  			t.Fatalf("err: %s", err)
    82  		}
    83  		if err := persister.PersistState(); err != nil {
    84  			t.Fatalf("err: %s", err)
    85  		}
    86  
    87  		if reader.State().Serial != serial {
    88  			t.Fatalf("bad: expected %d, got %d", serial, reader.State().Serial)
    89  		}
    90  
    91  		// Change the serial
    92  		currentCopy := *current
    93  		current = &currentCopy
    94  		current.Modules = []*terraform.ModuleState{
    95  			&terraform.ModuleState{
    96  				Path:    []string{"root", "somewhere"},
    97  				Outputs: map[string]string{"serialCheck": "true"},
    98  			},
    99  		}
   100  		if err := writer.WriteState(current); err != nil {
   101  			t.Fatalf("err: %s", err)
   102  		}
   103  		if err := persister.PersistState(); err != nil {
   104  			t.Fatalf("err: %s", err)
   105  		}
   106  
   107  		if reader.State().Serial <= serial {
   108  			t.Fatalf("bad: expected %d, got %d", serial, reader.State().Serial)
   109  		}
   110  
   111  		// Check that State() returns a copy
   112  		reader.State().Serial++
   113  		if reflect.DeepEqual(reader.State(), current) {
   114  			t.Fatal("State() should return a copy")
   115  		}
   116  	}
   117  }
   118  
   119  // TestStateInitial is the initial state that a State should have
   120  // for TestState.
   121  func TestStateInitial() *terraform.State {
   122  	initial := &terraform.State{
   123  		Modules: []*terraform.ModuleState{
   124  			&terraform.ModuleState{
   125  				Path: []string{"root", "child"},
   126  				Outputs: map[string]string{
   127  					"foo": "bar",
   128  				},
   129  			},
   130  		},
   131  	}
   132  
   133  	var scratch bytes.Buffer
   134  	terraform.WriteState(initial, &scratch)
   135  	return initial
   136  }