Add pr file matchers (#9)

* Add pr file matchers

* Quick refactors per PR comments

* Refactor getting of pr file names

* Removed unused param

* Only fetch PR files names once

.github/labeler.yml

@@ -1,2 +1,7 @@
-  TestLabel:
-        title: ".*"
+TestLabel:
+  title: ".*"
+TestFileMatch:
+  files: 
+    - "cmd/.*.go"
+    - "pkg/.*.go"
+

README.md

@@ -85,6 +85,21 @@ This condition is satisfied when the PR title matches on the given regex.
     WIP:
       title: "^WIP:.*"
 
+### Regex on branch
+
+This condition is satisfied when the PR branch matches on the given regex.
+
+    Feature:
+      branch: "^feature/.*"
+
+### Regex on PR files
+
+This condition is satisfied when any of the PR files matches on the given regexs.
+
+    Tests:
+      files: 
+        - "cmd/.*_tests.go"
+
 ### Mergeable status
 
 This condition is satisfied when the PR is in a [mergeable state](https://developer.github.com/v3/pulls/#response-1).

go.mod

@@ -9,5 +9,5 @@ require (
 	github.com/kr/pretty v0.1.0 // indirect
 	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
-	gopkg.in/yaml.v2 v2.2.2 // indirect
+	github.com/waigani/diffparser v0.0.0-20190828052634-7391f219313d
 )

go.sum

@@ -1,3 +1,5 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-yaml/yaml v2.1.0+incompatible h1:RYi2hDdss1u4YE7GwixGzWwVo47T8UQwnTLB6vQiq+o=
 github.com/go-yaml/yaml v2.1.0+incompatible/go.mod h1:w2MrLa16VYP0jy6N7M5kHaCkaLENm+P+Tv+MfurjSw0=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
@@ -13,6 +15,11 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/waigani/diffparser v0.0.0-20190828052634-7391f219313d h1:xQcF7b7cZLWZG/+7A4G7un1qmEDYHIvId9qxRS1mZMs=
+github.com/waigani/diffparser v0.0.0-20190828052634-7391f219313d/go.mod h1:BzSc3WEF8R+lCaP5iGFRxd5kIXy4JKOZAwNe1w0cdc0=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=

pkg/labeler.go

@@ -2,18 +2,24 @@ package labeler
 
 import (
 	"fmt"
+	"io/ioutil"
 	"log"
 	"math"
+	"net/http"
+	"os"
 	"regexp"
 	"strconv"
+	"strings"
 
 	gh "github.com/google/go-github/v27/github"
+	"github.com/waigani/diffparser"
 )
 
 type LabelerConfig map[string]LabelMatcher
 type LabelMatcher struct {
 	Title     string
 	Branch    string
+	Files     []string
 	Mergeable string
 	SizeBelow string `yaml:"size-below"`
 	SizeAbove string `yaml:"size-above"`
@@ -68,6 +74,41 @@ func NewBranchCondition() Condition {
 	}
 }
 
+func NewFilesCondition() Condition {
+	prFiles := []string{}
+
+	return Condition{
+		GetName: func() string {
+			return "File matches regex"
+		},
+		Evaluate: func(pr *gh.PullRequest, matcher LabelMatcher) (bool, error) {
+			if len(matcher.Files) <= 0 {
+				return false, fmt.Errorf("Files are not set in config")
+			}
+
+			if len(prFiles) == 0 {
+				var err error
+				prFiles, err = getPrFileNames(pr)
+				if err != nil {
+					return false, err
+				}
+			}
+
+			log.Printf("Matching `%s` against: %s", strings.Join(matcher.Files, ", "), strings.Join(prFiles, ", "))
+			for _, fileMatcher := range matcher.Files {
+				for _, prFile := range prFiles {
+					isMatched, _ := regexp.Match(fileMatcher, []byte(prFile))
+					if isMatched {
+						log.Printf("Matched `%s` against: `%s`", prFile, fileMatcher)
+						return isMatched, nil
+					}
+				}
+			}
+			return false, nil
+		},
+	}
+}
+
 func NewIsMergeableCondition() Condition {
 	return Condition{
 		GetName: func() string {
@@ -184,6 +225,7 @@ func (l *Labeler) findMatches(pr *gh.PullRequest, config *LabelerConfig) (LabelU
 		NewBranchCondition(),
 		NewIsMergeableCondition(),
 		NewSizeCondition(),
+		NewFilesCondition(),
 	}
 
 	for label, matcher := range *config {
@@ -204,3 +246,46 @@ func (l *Labeler) findMatches(pr *gh.PullRequest, config *LabelerConfig) (LabelU
 
 	return labelUpdates, nil
 }
+
+// getPrFileNames returns all of the file names (old and new) of files changed in the given PR
+func getPrFileNames(pr *gh.PullRequest) ([]string, error) {
+	ghToken := os.Getenv("GITHUB_TOKEN")
+	diffReq, err := http.NewRequest("GET", pr.GetDiffURL(), nil)
+
+	if err != nil {
+		return nil, err
+	}
+
+	diffReq.Header.Add("Authorization", "Bearer "+ghToken)
+	diffRes, err := http.DefaultClient.Do(diffReq)
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer diffRes.Body.Close()
+
+	var diffRaw []byte
+	prFiles := make([]string, 0)
+	if diffRes.StatusCode == http.StatusOK {
+		diffRaw, err = ioutil.ReadAll(diffRes.Body)
+
+		if err != nil {
+			return nil, err
+		}
+
+		diff, _ := diffparser.Parse(string(diffRaw))
+		prFilesSet := map[string]struct{}{}
+		// Place in a set to remove duplicates
+		for _, file := range diff.Files {
+			prFilesSet[file.OrigName] = struct{}{}
+			prFilesSet[file.NewName] = struct{}{}
+		}
+		// Convert to list to make it easier to consume
+		for k := range prFilesSet {
+			prFiles = append(prFiles, k)
+		}
+	}
+
+	return prFiles, nil
+}

pkg/labeler_test.go

@@ -172,6 +172,19 @@ func TestHandleEvent(t *testing.T) {
 			initialLabels:  []string{},
 			expectedLabels: []string{},
 		},
+		TestCase{
+			payloads: []string{"diff_pr"},
+			name:     "Test the branch rule",
+			config: LabelerConfig{
+				"Files": LabelMatcher{
+					Files: []string{
+						"^pkg/.*_test.go",
+					},
+				},
+			},
+			initialLabels:  []string{},
+			expectedLabels: []string{"Files"},
+		},
 	}
 
 	for _, tc := range testCases {