Merge pull request #147 from glesica/add-file-assertion

Add file assertion

Author: dylanhitt

CHANGELOG.md

@@ -2,6 +2,7 @@
 
  - Add ability to test suite from a url
  - Add ability to test suite from stdin
+ - Add `file` assertion to `stdout` and `stderr`
 
 # v2.3.0
 

README.md

@@ -40,6 +40,7 @@ For more information take a look at the [quick start](#quick-start), the [exampl
       * [line-count](#line-count)
       * [not-contains](#not-contains)
       * [xml](#xml)
+      * [file](#file)
     - [stderr](#stderr)
     - [skip](#skip)
   + [Config](#user-content-config-config)
@@ -167,6 +168,7 @@ 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
 
@@ -529,6 +531,21 @@ cat some.xml:
 </book>
 ```
 
+##### file
+
+`file` is a file path, relative to the working directory that will have
+its entire contents matched against the command output. Other than
+reading from a file this works the same as [exactly](#exactly).
+
+The example below will always pass.
+
+```yaml
+output should match file:
+  command: cat output.txt
+  stdout:
+    file: output.txt
+```
+
 #### stderr
 
 See [stdout](#stdout) for more information.

commander_unix.yaml

@@ -16,17 +16,18 @@ 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:
     command: ./commander test ./integration/unix/failing_suite.yaml
     stdout:
       contains:
+        - ✗ [local] 'file matcher should fail when file and output are different', on property 'Stdout'
         - ✗ [local] 'it will fail', on property 'ExitCode'
         - ✗ [local] 'test timeout' could not be executed with error message
         - Command timed out after 10ms
-        - "Count: 2, Failed: 2"
+        - "Count: 3, Failed: 3"
     exit-code: 1
 
   it should validate a big output:

examples/_fixtures/output.txt

@@ -0,0 +1,2 @@
+line one
+line two

examples/commander.yaml

@@ -24,4 +24,9 @@ tests:
   it should skip:
     command: echo "I should be skipped"
     stdout: I should be skipped
-    skip: true
+    skip: true
+
+  it should match file output:
+    command: printf "line one\nline two"
+    stdout:
+      file: ../../examples/_fixtures/output.txt

integration/unix/_fixtures/file_output_0.txt

@@ -0,0 +1,2 @@
+first line
+second line

integration/unix/_fixtures/file_output_1.txt

@@ -0,0 +1,3 @@
+first line
+second line
+third line

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

integration/unix/failing_suite.yaml

@@ -7,4 +7,9 @@ tests:
     command: sleep 1
     config:
       timeout: 10ms
-    exit-code: 0
+    exit-code: 0
+
+  file matcher should fail when file and output are different:
+    command: cat ./integration/unix/_fixtures/file_output_1.txt
+    stdout:
+      file: ./integration/unix/_fixtures/file_output_0.txt

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"
 )
@@ -20,8 +21,13 @@ const (
 	NotContains = "notcontains"
 	JSON        = "json"
 	XML         = "xml"
+	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 {
@@ -37,6 +43,8 @@ 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 +248,32 @@ 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 := 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,
+	}
+}