bitbucket: Implement ChecksByChange with per-status build detail

internal/forge/bitbucket/checks_report.go

@@ -2,18 +2,104 @@ package bitbucket
 
 import (
 	"context"
+	"fmt"
+	"strings"
 
 	"go.abhg.dev/gs/internal/forge"
+	"go.abhg.dev/gs/internal/gateway/bitbucket"
 )
 
-// ChecksByChange reports per-change rolled-up and per-run check state
-// for each of the given changes.
+// rollupFromCommitStatuses collapses a Bitbucket build-status list into
+// the forge rollup taxonomy.
 //
-// TODO: real implementation lands on a follow-up branch.
-// This stub returns one nil per id to satisfy the [forge.Repository]
-// interface while the schema branch lands standalone.
+// Failure wins over pending; pending wins over passed; absence of any
+// statuses returns ChecksRollupNone (no CI configured/reported).
+// Stopped statuses are operator-cancelled non-failures and roll up as
+// passed.
+func rollupFromCommitStatuses(
+	statuses []bitbucket.CommitStatus,
+) forge.ChecksRollupState {
+	if len(statuses) == 0 {
+		return forge.ChecksRollupNone
+	}
+
+	pending := false
+	for _, s := range statuses {
+		switch s.State {
+		case bitbucket.CommitStatusFailed:
+			return forge.ChecksRollupFailed
+		case bitbucket.CommitStatusInProgress:
+			pending = true
+		}
+	}
+	if pending {
+		return forge.ChecksRollupPending
+	}
+	return forge.ChecksRollupPassed
+}
+
+// ChecksByChange reports per-change rolled-up and per-run build state
+// for each of the given pull requests.
+//
+// One getPullRequest + (when the PR has a source commit) a paginated
+// CommitStatusList walk per PR. Build statuses are reported in
+// Bitbucket's natural order.
 func (r *Repository) ChecksByChange(
-	_ context.Context, ids []forge.ChangeID,
+	ctx context.Context, ids []forge.ChangeID,
 ) ([]*forge.ChecksReport, error) {
-	return make([]*forge.ChecksReport, len(ids)), nil
+	out := make([]*forge.ChecksReport, len(ids))
+	for i, id := range ids {
+		checks, err := r.changeChecks(ctx, id)
+		if err != nil {
+			return nil, fmt.Errorf("change %v: %w", id, err)
+		}
+		out[i] = checks
+	}
+	return out, nil
+}
+
+func (r *Repository) changeChecks(
+	ctx context.Context, id forge.ChangeID,
+) (*forge.ChecksReport, error) {
+	prID := mustPR(id)
+	pr, err := r.getPullRequest(ctx, prID.Number)
+	if err != nil {
+		return nil, fmt.Errorf("get pull request: %w", err)
+	}
+
+	if pr.Source.Commit == nil {
+		return &forge.ChecksReport{Rollup: forge.ChecksRollupNone}, nil
+	}
+
+	var statuses []bitbucket.CommitStatus
+	opt := &bitbucket.CommitStatusListOptions{}
+	for {
+		page, resp, err := r.client.CommitStatusList(
+			ctx, r.workspace, r.repo, pr.Source.Commit.Hash, opt,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("get commit statuses: %w", err)
+		}
+
+		statuses = append(statuses, page.Values...)
+		if resp.NextURL == "" {
+			break
+		}
+		opt.PageURL = resp.NextURL
+	}
+
+	out := &forge.ChecksReport{Rollup: rollupFromCommitStatuses(statuses)}
+	out.Runs = make([]forge.CheckRun, 0, len(statuses))
+	for _, s := range statuses {
+		name := s.Name
+		if name == "" {
+			name = s.Key
+		}
+		out.Runs = append(out.Runs, forge.CheckRun{
+			Name:  name,
+			State: strings.ToLower(s.State),
+			URL:   s.URL,
+		})
+	}
+	return out, nil
 }

internal/forge/bitbucket/checks_report_test.go

@@ -0,0 +1,68 @@
+package bitbucket
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.abhg.dev/gs/internal/forge"
+	"go.abhg.dev/gs/internal/gateway/bitbucket"
+)
+
+func TestRollupFromCommitStatuses(t *testing.T) {
+	tests := []struct {
+		name     string
+		statuses []bitbucket.CommitStatus
+		want     forge.ChecksRollupState
+	}{
+		{
+			name: "Empty",
+			want: forge.ChecksRollupNone,
+		},
+		{
+			name: "AllSuccessful",
+			statuses: []bitbucket.CommitStatus{
+				{State: bitbucket.CommitStatusSuccessful},
+				{State: bitbucket.CommitStatusSuccessful},
+			},
+			want: forge.ChecksRollupPassed,
+		},
+		{
+			name: "Failed",
+			statuses: []bitbucket.CommitStatus{
+				{State: bitbucket.CommitStatusSuccessful},
+				{State: bitbucket.CommitStatusFailed},
+			},
+			want: forge.ChecksRollupFailed,
+		},
+		{
+			name: "InProgress",
+			statuses: []bitbucket.CommitStatus{
+				{State: bitbucket.CommitStatusSuccessful},
+				{State: bitbucket.CommitStatusInProgress},
+			},
+			want: forge.ChecksRollupPending,
+		},
+		{
+			name: "FailedTrumpsInProgress",
+			statuses: []bitbucket.CommitStatus{
+				{State: bitbucket.CommitStatusInProgress},
+				{State: bitbucket.CommitStatusFailed},
+			},
+			want: forge.ChecksRollupFailed,
+		},
+		{
+			name: "StoppedIsPassed",
+			statuses: []bitbucket.CommitStatus{
+				{State: bitbucket.CommitStatusSuccessful},
+				{State: bitbucket.CommitStatusStopped},
+			},
+			want: forge.ChecksRollupPassed,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, rollupFromCommitStatuses(tt.statuses))
+		})
+	}
+}

internal/gateway/bitbucket/api.go

@@ -404,6 +404,13 @@ func (c *Client) PullRequestMerge(
 type CommitStatus struct {
 	Key   string `json:"key"`
 	State string `json:"state"`
+
+	// Name is the human-readable label for the build status, if any.
+	// Falls back to Key when empty.
+	Name string `json:"name,omitempty"`
+
+	// URL links to the build's detail page, if any.
+	URL string `json:"url,omitempty"`
 }
 
 // CommitStatusCreateRequest is the request body for creating a build status.