Created more test cases, added in env section

Author: bchadwic

git/fixtures/simple.git/config

@@ -7,3 +7,9 @@
 [user]
 	name = Mona the Cat
 	email = monalisa@github.com
+[remote "origin"]
+	url = git@github.com:monathecat/cli.git
+    fetch = +refs/heads/*:refs/remotes/origin/*
+[remote "upstream"]
+	url = git@github.com:cli/cli.git
+    fetch = +refs/heads/trunk:refs/remotes/upstream/trunk

pkg/cmd/repo/default/default.go

@@ -36,8 +36,22 @@ func NewCmdDefault(f *cmdutil.Factory) *cobra.Command {
 		repository gh should automatically point to.
 		`),
 		Example: heredoc.Doc(`
-			$ gh repo default cli/cli
+			$ gh repo default
+			#=> prompts remote options
+
+			$ gh repo default -v
+			#=> cli/cli
 		`),
+		Annotations: map[string]string{
+			"help:environment": heredoc.Doc(`
+				To manually configure a remote for gh to use, modify your local repo's git config
+
+				; Ex: setting gh to use the upstream remote
+				[remote "upstream"]
+ 					gh-resolved = base
+				...
+			`),
+		},
 		Args: cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runDefault(opts)

pkg/cmd/repo/default/default_test.go

@@ -4,24 +4,27 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"os"
 	"testing"
 
 	"github.com/cli/cli/v2/context"
 	"github.com/cli/cli/v2/git"
 	"github.com/cli/cli/v2/internal/ghrepo"
-	"github.com/cli/cli/v2/pkg/httpmock"
 	"github.com/cli/cli/v2/pkg/iostreams"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_defaultRun(t *testing.T) {
+	setGitDir(t, "../../../../git/fixtures/simple.git")
 	tests := []struct {
-		name         string
-		opts         DefaultOptions
-		wantedErr    error
-		wantedStdOut string
+		name               string
+		opts               DefaultOptions
+		wantedErr          error
+		wantedStdOut       string
+		wantedResolvedName string
 	}{
 		{
+			name: "Base repo set with view option",
 			opts: DefaultOptions{
 				Remotes: func() (context.Remotes, error) {
 					return []*context.Remote{
@@ -39,35 +42,50 @@ func Test_defaultRun(t *testing.T) {
 			wantedStdOut: "hubot/Spoon-Knife",
 		},
 		{
+			name: "Base repo not set with view option",
 			opts: DefaultOptions{
 				Remotes: func() (context.Remotes, error) {
 					return []*context.Remote{
 						{
 							Remote: &git.Remote{
 								Name: "origin",
 							},
-							Repo: ghrepo.New("hubot", "Spoon-Knife"),
 						},
 					}, nil
 				},
 				ViewFlag: true,
 			},
 			wantedErr: errors.New("a default repo has not been set, use `gh repo default` to set a default repo"),
 		},
+		{
+			name: "Base repo not set, assign non-interactively",
+			opts: DefaultOptions{
+				Remotes: func() (context.Remotes, error) {
+					return []*context.Remote{
+						{
+							Remote: &git.Remote{
+								Name: "origin",
+							},
+						},
+						{
+							Remote: &git.Remote{
+								Name: "upstream",
+							},
+						},
+					}, nil
+				},
+			},
+			wantedResolvedName: "upstream",
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			io, _, stdout, stderr := iostreams.Test()
 
-			reg := httpmock.Registry{}
-			defer reg.Verify(t)
-
 			opts := tt.opts
 			opts.IO = io
-			opts.HttpClient = func() (*http.Client, error) {
-				return &http.Client{Transport: &reg}, nil
-			}
+			opts.HttpClient = func() (*http.Client, error) { return nil, nil }
 
 			err := runDefault(&opts)
 			if tt.wantedErr != nil {
@@ -81,6 +99,29 @@ func Test_defaultRun(t *testing.T) {
 					assert.Equal(t, "", stderr.String())
 				}
 			}
+			if tt.wantedResolvedName != "" {
+				resolvedAmount := 0
+				remotes, err := git.Remotes()
+				if err != nil {
+					panic(err)
+				}
+				for _, r := range remotes {
+					if r.Resolved == "base" {
+						assert.Equal(t, r.Name, tt.wantedResolvedName)
+						resolvedAmount++
+					}
+				}
+				assert.Equal(t, 1, resolvedAmount)
+			}
 		})
 	}
 }
+
+func setGitDir(t *testing.T, dir string) {
+	old_GIT_DIR := os.Getenv("GIT_DIR")
+	os.Setenv("GIT_DIR", dir)
+	t.Cleanup(func() {
+		git.UnsetRemoteResolution("upstream")
+		os.Setenv("GIT_DIR", old_GIT_DIR)
+	})
+}