Implement file matcher / assertion

Author: glesica

CHANGELOG.md

@@ -1,6 +1,7 @@
 # v2.4.0
 
  - Add ability to test suite from a url
+ - Add `file` assertion to `stdout` and `stderr`
 
 # v2.3.0
 

README.md

@@ -167,6 +167,7 @@ tests:
                 object.attr: hello # Make assertions on json objects
             xml:
                 "//book//auhtor": Steven King # Make assertions on xml documents
+            file: correct-output.txt
         exit-code: 127
         skip: false
 

commander_unix.yaml

@@ -16,7 +16,7 @@ tests:
       contains:
         - ✓ [local] it should exit with error code
         - "- [local] it should skip, was skipped"
-      line-count: 17
+      line-count: 19
     exit-code: 0
 
   it should assert that commander will fail:

integration/unix/commander_test.yaml

@@ -59,6 +59,16 @@ tests:
         /books/0/author: J. R. R. Tokien
         /books/1/author: Joanne K. Rowling
 
+  it should assert file contents on stdout:
+    command: cat ./integration/unix/_fixtures/big_out.txt
+    stdout:
+      file: ./integration/unix/_fixtures/big_out.txt
+
+  it should assert file contents on stderr:
+    command: cat ./integration/unix/_fixtures/big_out.txt >&2
+    stderr:
+      file: ./integration/unix/_fixtures/big_out.txt
+
   it should inherit from parent env:
     config:
       inherit-env: true

pkg/matcher/matcher.go

@@ -5,6 +5,7 @@ import (
 	"github.com/antchfx/xmlquery"
 	"github.com/pmezard/go-difflib/difflib"
 	"github.com/tidwall/gjson"
+	"io/ioutil"
 	"log"
 	"strings"
 )
@@ -20,6 +21,7 @@ const (
 	NotContains = "notcontains"
 	JSON        = "json"
 	XML         = "xml"
+	File        = "file"
 )
 
 // NewMatcher creates a new matcher by type
@@ -37,6 +39,8 @@ func NewMatcher(matcher string) Matcher {
 		return JSONMatcher{}
 	case XML:
 		return XMLMatcher{}
+	case File:
+		return FileMatcher{}
 	default:
 		panic(fmt.Sprintf("Validator '%s' does not exist!", matcher))
 	}
@@ -240,3 +244,32 @@ to be equal to
 
 	return result
 }
+
+// FileMatcher matches output captured from stdout or stderr
+// against the contents of a file
+type FileMatcher struct {
+}
+
+func (m FileMatcher) Match(got interface{}, expected interface{}) MatcherResult {
+	expectedText, err := ioutil.ReadFile(expected.(string))
+	if err != nil {
+		panic(err.Error())
+	}
+	expectedString := string(expectedText)
+
+	result := got == expectedString
+
+	diff := difflib.UnifiedDiff{
+		A:        difflib.SplitLines(got.(string)),
+		B:        difflib.SplitLines(expectedString),
+		FromFile: "Got",
+		ToFile:   "Expected",
+		Context:  3,
+	}
+	diffText, _ := difflib.GetUnifiedDiffString(diff)
+
+	return MatcherResult{
+		Diff:    diffText,
+		Success: result,
+	}
+}

pkg/matcher/matcher_test.go

@@ -48,16 +48,16 @@ func TestTextMatcher_ValidateFails(t *testing.T) {
 
 func TestEqualMatcher_Validate(t *testing.T) {
 	m := EqualMatcher{}
-	got := m.Match(1, 1)
+	got := m.Match(2, 2)
 	assert.True(t, got.Success)
 }
 
 func TestEqualMatcher_ValidateFails(t *testing.T) {
 	m := EqualMatcher{}
-	got := m.Match(1, 0)
+	got := m.Match(2, 3)
 	assert.False(t, got.Success)
-	assert.Contains(t, got.Diff, "+0")
-	assert.Contains(t, got.Diff, "-1")
+	assert.Contains(t, got.Diff, "+3")
+	assert.Contains(t, got.Diff, "-2")
 }
 
 func TestContainsMatcher_Match(t *testing.T) {
@@ -183,3 +183,19 @@ another`
 	assert.False(t, r.Success)
 	assert.Equal(t, diff, r.Diff)
 }
+
+func TestFileMatcher_Validate(t *testing.T) {
+	m := FileMatcher{}
+	got := m.Match("zoom", "zoom.txt")
+	assert.True(t, got.Success)
+	assert.Equal(t, "", got.Diff)
+}
+
+func TestFileMatcher_ValidateFails(t *testing.T) {
+	m := FileMatcher{}
+	got := m.Match("zoom", "zoologist.txt")
+	assert.False(t, got.Success)
+	println(got.Diff)
+	assert.Contains(t, got.Diff, "+zoologist")
+	assert.Contains(t, got.Diff, "-zoom")
+}

pkg/matcher/zoologist.txt

@@ -0,0 +1 @@
+zoologist

pkg/matcher/zoom.txt

@@ -0,0 +1 @@
+zoom

pkg/runtime/runtime.go

@@ -99,6 +99,7 @@ type ExpectedOut struct {
 	NotContains []string          `yaml:"not-contains,omitempty"`
 	JSON        map[string]string `yaml:"json,omitempty"`
 	XML         map[string]string `yaml:"xml,omitempty"`
+	File        string            `yaml:"file,omitempty"`
 }
 
 // CommandUnderTest represents the command under test

pkg/runtime/validator.go

@@ -118,6 +118,13 @@ func validateExpectedOut(got string, expected ExpectedOut) matcher.MatcherResult
 		}
 	}
 
+	if expected.File != "" {
+		m = matcher.NewMatcher(matcher.File)
+		if result = m.Match(got, expected.File); !result.Success {
+			return result
+		}
+	}
+
 	return result
 }