Add tests for build resolver

internal/build/resolver/current_branch.go

@@ -19,7 +19,7 @@ func ResolveBuildFromCurrentBranch(branch string, pipelineResolver pipelineResol
 			return nil, err
 		}
 		if pipeline == nil {
-			return nil, fmt.Errorf("Failed to resolve a pipeline (%s) to query builds on.", pipeline.Name)
+			return nil, fmt.Errorf("Failed to resolve a pipeline to query builds on.")
 		}
 
 		b, err := graphql.RecentBuildsForBranch(ctx, f.GraphQLClient, branch, fmt.Sprintf("%s/%s", pipeline.Org, pipeline.Name))

internal/build/resolver/current_branch_test.go

@@ -0,0 +1,108 @@
+package resolver_test
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+
+	genqlient "github.com/Khan/genqlient/graphql"
+	"github.com/buildkite/cli/v3/internal/build/resolver"
+	"github.com/buildkite/cli/v3/internal/graphql"
+	"github.com/buildkite/cli/v3/internal/pipeline"
+	"github.com/buildkite/cli/v3/pkg/cmd/factory"
+)
+
+func TestResolveBuildFromCurrentBranch(t *testing.T) {
+	t.Parallel()
+	t.Run("Can resolve a build from graphql", func(t *testing.T) {
+		t.Parallel()
+		mock := genqlient.Response{
+			Data: &graphql.RecentBuildsForBranchResponse{
+				Pipeline: &graphql.RecentBuildsForBranchPipeline{
+					Builds: &graphql.RecentBuildsForBranchPipelineBuildsBuildConnection{
+						Edges: []*graphql.RecentBuildsForBranchPipelineBuildsBuildConnectionEdgesBuildEdge{
+							{
+								Node: &graphql.RecentBuildsForBranchPipelineBuildsBuildConnectionEdgesBuildEdgeNodeBuild{
+									Number: 42,
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+		f := factory.Factory{
+			GraphQLClient: genqlient.NewClient("", mockDoer(&mock)),
+		}
+		r := resolver.ResolveBuildFromCurrentBranch("testing", pipelineResolver, &f)
+		b, err := r(context.Background())
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if b.BuildNumber != 42 {
+			t.Errorf("Build number did not match 42: %d", b.BuildNumber)
+		}
+	})
+
+	t.Run("Errors if no builds are found", func(t *testing.T) {
+		t.Parallel()
+		mock := genqlient.Response{
+			Data: &graphql.RecentBuildsForBranchResponse{
+				Pipeline: &graphql.RecentBuildsForBranchPipeline{
+					Builds: &graphql.RecentBuildsForBranchPipelineBuildsBuildConnection{
+						Edges: []*graphql.RecentBuildsForBranchPipelineBuildsBuildConnectionEdgesBuildEdge{},
+					},
+				},
+			},
+		}
+		f := factory.Factory{
+			GraphQLClient: genqlient.NewClient("", mockDoer(&mock)),
+		}
+		r := resolver.ResolveBuildFromCurrentBranch("testing", pipelineResolver, &f)
+		_, err := r(context.Background())
+
+		if err.Error() != "No builds found for pipeline test pipeline, branch testing" {
+			t.Fatal(err)
+		}
+	})
+
+	t.Run("Errors if pipeline cannot be resovled", func(t *testing.T) {
+		t.Parallel()
+		r := resolver.ResolveBuildFromCurrentBranch("testing", func(context.Context) (*pipeline.Pipeline, error) { return nil, nil }, &factory.Factory{})
+		_, err := r(context.Background())
+
+		if err.Error() != "Failed to resolve a pipeline to query builds on." {
+			t.Fatal(err)
+		}
+	})
+}
+
+type doer struct {
+	obj any
+}
+
+// Do implements graphql.Doer.
+func (d doer) Do(*http.Request) (*http.Response, error) {
+	j, _ := json.Marshal(d.obj)
+
+	return &http.Response{
+		StatusCode: http.StatusOK,
+		Body:       io.NopCloser(bytes.NewBuffer(j)),
+	}, nil
+}
+
+func mockDoer(obj any) genqlient.Doer {
+	return doer{obj}
+}
+
+func pipelineResolver(context.Context) (*pipeline.Pipeline, error) {
+	return &pipeline.Pipeline{
+		Org:  "test org",
+		Name: "test pipeline",
+	}, nil
+}