Add unit tests for getting a size of a pull request

Author: kkohtaka

cmd/gh-actions-pr-size/github.go

@@ -42,16 +42,16 @@ func getAllPullRequestFiles(
 	return res, nil
 }
 
-// getPullRequestSize determines a size of a pull request by calculating a total number of changed lines.
-func getPullRequestSize(
+// getPullRequestSize returns the total number of changed lines of the specified pull request.
+func getPullRequestChangedLines(
 	ctx context.Context,
 	client *github.Client,
 	owner, repo string,
 	number int,
-) (size, error) {
+) (int, error) {
 	files, err := getAllPullRequestFiles(ctx, client, owner, repo, number)
 	if err != nil {
-		return sizeUnknown, fmt.Errorf("get all commit files: %w", err)
+		return 0, fmt.Errorf("get all commit files: %w", err)
 	}
 
 	// TODO(kkohtaka): Filter out linguist-generated files
@@ -60,7 +60,7 @@ func getPullRequestSize(
 	for _, file := range files {
 		change += *file.Additions + *file.Deletions
 	}
-	return newSize(change), nil
+	return change, nil
 }
 
 // setLabelOnPullRequest checks the current labels on the pull request.  If there exists a label for pull request size,

cmd/gh-actions-pr-size/github_test.go

@@ -0,0 +1,151 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/google/go-github/v29/github"
+	"github.com/jarcoal/httpmock"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetPullRequestChangedLines(t *testing.T) {
+	tcs := []struct {
+		name        string
+		commitFiles [][]*github.CommitFile
+		want        int
+	}{
+		{
+			name: "The target pull request changes a single file.",
+			commitFiles: [][]*github.CommitFile{
+				{
+					{
+						Additions: github.Int(100),
+						Deletions: github.Int(200),
+					},
+				},
+			},
+			want: 300,
+		},
+		{
+			name: "The target pull request changes multiple files.",
+			commitFiles: [][]*github.CommitFile{
+				{
+					{
+						Additions: github.Int(100),
+						Deletions: github.Int(200),
+					},
+					{
+						Additions: github.Int(300),
+						Deletions: github.Int(400),
+					},
+				},
+			},
+			want: 1000,
+		},
+		{
+			name: "The target pull request changes multiple files with pagenation.",
+			commitFiles: [][]*github.CommitFile{
+				{
+					{
+						Additions: github.Int(100),
+						Deletions: github.Int(200),
+					},
+				},
+				{
+					{
+						Additions: github.Int(300),
+						Deletions: github.Int(400),
+					},
+				},
+				{
+					{
+						Additions: github.Int(500),
+						Deletions: github.Int(600),
+					},
+				},
+			},
+			want: 2100,
+		},
+	}
+	for _, tt := range tcs {
+		t.Run(tt.name, func(t *testing.T) {
+			client := &http.Client{}
+			httpmock.ActivateNonDefault(client)
+			defer httpmock.DeactivateAndReset()
+
+			const baseURL = "https://api.github.com/repos/kkohtaka/gh-actions-pr-size/pulls/42/files"
+			httpmock.RegisterResponder(
+				"GET",
+				baseURL,
+				func(req *http.Request) (*http.Response, error) {
+					page := 1
+					if v, ok := req.URL.Query()["page"]; ok && len(v) > 0 {
+						if v, err := strconv.Atoi(v[0]); err == nil {
+							page = v
+						}
+					}
+					if page-1 >= len(tt.commitFiles) {
+						return nil, fmt.Errorf("invalid query value")
+					}
+
+					var links []string
+					links = append(links, fmt.Sprintf(`<%s?page=%d>; rel="first"`, baseURL, 1))
+					if page-1 >= 1 {
+						links = append(links, fmt.Sprintf(`<%s?page=%d>; rel="prev"`, baseURL, page-1))
+					}
+					if page+1 <= len(tt.commitFiles) {
+						links = append(links, fmt.Sprintf(`<%s?page=%d>; rel="next"`, baseURL, page+1))
+					}
+					links = append(links, fmt.Sprintf(`<%s?page=%d>; rel="last"`, baseURL, len(tt.commitFiles)))
+
+					resp, err := httpmock.NewJsonResponse(200, tt.commitFiles[page-1])
+					if err != nil {
+						return nil, err
+					}
+					resp.Header.Set("Content-Type", "application/json")
+					resp.Header.Set("Link", strings.Join(links, ", "))
+					return resp, nil
+				},
+			)
+
+			got, err := getPullRequestChangedLines(
+				context.Background(),
+				github.NewClient(client),
+				"kkohtaka",
+				"gh-actions-pr-size",
+				42,
+			)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func TestGetPullRequestChangedLinesReturnsError(t *testing.T) {
+	client := &http.Client{}
+	httpmock.ActivateNonDefault(client)
+	defer httpmock.DeactivateAndReset()
+
+	const baseURL = "https://api.github.com/repos/kkohtaka/gh-actions-pr-size/pulls/42/files"
+	httpmock.RegisterResponder(
+		"GET",
+		baseURL,
+		httpmock.NewErrorResponder(fmt.Errorf("test for error handling")),
+	)
+
+	got, err := getPullRequestChangedLines(
+		context.Background(),
+		github.NewClient(client),
+		"kkohtaka",
+		"gh-actions-pr-size",
+		42,
+	)
+	assert.ErrorContains(t, err, "get all commit files: list commit files: ")
+	assert.Zero(t, got)
+}

cmd/gh-actions-pr-size/main.go

@@ -64,10 +64,12 @@ func main() {
 	}
 	client := github.NewClient(tc)
 
-	size, err := getPullRequestSize(ctx, client, owner, repo, number)
+	changed, err := getPullRequestChangedLines(ctx, client, owner, repo, number)
 	if err != nil {
-		logger.Fatal("Could not get pull request size", zap.Error(err))
+		logger.Fatal("Could not get the total number of changed lines in the pull request", zap.Error(err))
 	}
+
+	size := newSize(changed)
 	logger.Info("Got a size of a pull request", zap.String("size", size.String()))
 
 	err = setLabelOnPullRequest(ctx, client, owner, repo, number, size)

go.mod

@@ -4,6 +4,8 @@ go 1.14
 
 require (
 	github.com/google/go-github/v29 v29.0.3
+	github.com/jarcoal/httpmock v1.2.0
+	github.com/stretchr/testify v1.7.1
 	go.uber.org/zap v1.21.0
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
 )

go.sum

@@ -11,19 +11,26 @@ github.com/google/go-github/v29 v29.0.3 h1:IktKCTwU//aFHnpA+2SLIi7Oo9uhAzgsdZNbc
 github.com/google/go-github/v29 v29.0.3/go.mod h1:CHKiKKPHJ0REzfwc14QMklvtHwCveD0PxlMjLlzAM5E=
 github.com/google/go-querystring v1.0.0 h1:Xkwi/a1rcvNg1PPYe5vI8GbeBY/jrVuDX5ASuANWTrk=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
+github.com/jarcoal/httpmock v1.2.0 h1:gSvTxxFR/MEMfsGrvRbdfpRUMBStovlSRLw0Ep1bwwc=
+github.com/jarcoal/httpmock v1.2.0/go.mod h1:oCoTsnAz4+UoOUIf5lJOWV2QQIW5UoeUI6aM2YnWAZk=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
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 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/maxatome/go-testdeep v1.11.0 h1:Tgh5efyCYyJFGUYiT0qxBSIDeXw0F5zSoatlou685kk=
+github.com/maxatome/go-testdeep v1.11.0/go.mod h1:011SgQ6efzZYAen6fDn4BqQ+lUR72ysdyKe7Dyogw70=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
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