Add validator test and allow fake ReadFile

Author: glesica

pkg/matcher/matcher.go

@@ -24,6 +24,10 @@ const (
 	File        = "file"
 )
 
+// The function used to open files when necessary for matching
+// Allows the file IO to be overridden during tests
+var ReadFile = ioutil.ReadFile
+
 // NewMatcher creates a new matcher by type
 func NewMatcher(matcher string) Matcher {
 	switch matcher {
@@ -251,7 +255,7 @@ type FileMatcher struct {
 }
 
 func (m FileMatcher) Match(got interface{}, expected interface{}) MatcherResult {
-	expectedText, err := ioutil.ReadFile(expected.(string))
+	expectedText, err := ReadFile(expected.(string))
 	if err != nil {
 		panic(err.Error())
 	}

pkg/matcher/matcher_test.go

@@ -184,18 +184,23 @@ another`
 	assert.Equal(t, diff, r.Diff)
 }
 
-func TestFileMatcher_Validate(t *testing.T) {
+func TestFileMatcher_Match(t *testing.T) {
+	ReadFile = func(filename string) ([]byte, error) {
+		return []byte("line one\nline two"), nil
+	}
 	m := FileMatcher{}
-	got := m.Match("zoom", "zoom.txt")
+	got := m.Match("line one\nline two", "fake.txt")
 	assert.True(t, got.Success)
 	assert.Equal(t, "", got.Diff)
 }
 
 func TestFileMatcher_ValidateFails(t *testing.T) {
+	ReadFile = func(filename string) ([]byte, error) {
+		return []byte("line one\nline two"), nil
+	}
 	m := FileMatcher{}
-	got := m.Match("zoom", "zoologist.txt")
+	got := m.Match("line one\nline three", "fake.txt")
 	assert.False(t, got.Success)
-	println(got.Diff)
-	assert.Contains(t, got.Diff, "+zoologist")
-	assert.Contains(t, got.Diff, "-zoom")
+	assert.Contains(t, got.Diff, "+line two")
+	assert.Contains(t, got.Diff, "-line three")
 }

pkg/matcher/zoologist.txt

@@ -3,6 +3,7 @@ package runtime
 import (
 	"github.com/commander-cli/commander/pkg/matcher"
 	"github.com/stretchr/testify/assert"
+	"io/ioutil"
 	"testing"
 )
 
@@ -192,6 +193,29 @@ test`
 	assert.Equal(t, diff, r.Diff)
 }
 
+func Test_ValidateExpectedOut_ValidateFile(t *testing.T) {
+	content := "line one"
+	matcher.ReadFile = func(filename string) ([]byte, error) {
+		return []byte(content), nil
+	}
+	r := validateExpectedOut(content, ExpectedOut{File: "fake.txt"})
+	assert.True(t, r.Success)
+	assert.Equal(t, "", r.Diff)
+
+	diff := `--- Got
++++ Expected
+@@ -1,2 +1 @@
+ line one
+-line two
+`
+
+	r = validateExpectedOut(content+"\nline two", ExpectedOut{File: "fake.txt"})
+	assert.False(t, r.Success)
+	assert.Equal(t, diff, r.Diff)
+
+	matcher.ReadFile = ioutil.ReadFile
+}
+
 func Test_ValidateExpectedOut_ValidateXML(t *testing.T) {
 	xml := `<book>
   <author>J. R. R. Tolkien</author>