submit: add --fill-from parameter for stack submission commands

.changes/unreleased/Added-20260513-113740.yaml

@@ -0,0 +1,3 @@
+kind: Added
+body: Add --fill-from parameter to upstack, downstack, and stack commands to allow autofilling of CR titles/bodies when submitting whole stacks.
+time: 2026-05-13T11:37:40.724695-07:00

doc/includes/cli-reference.md

@@ -277,6 +277,7 @@ only if there are multiple CRs in the stack.
 * `-r`, `--reviewer=REVIEWER,...`: Add reviewers to the change request. Pass multiple times or separate with commas. <span class="mdx-badge"><span class="mdx-badge__icon">:material-tag:{ title="Released in version" }</span><span class="mdx-badge__text">[v0.21.0](/changelog.md#v0.21.0)</span>
 * `-a`, `--assign=ASSIGNEE,...`: Assign the change request to these users. Pass multiple times or separate with commas. <span class="mdx-badge"><span class="mdx-badge__icon">:material-tag:{ title="Released in version" }</span><span class="mdx-badge__text">[v0.21.0](/changelog.md#v0.21.0)</span>
 * `--no-web`: Alias for --web=false.
+* `--fill-from=FILE`: JSON file mapping branch names to {title, body} for CR creation. Use '-' for stdin.
 
 **Configuration**: [spice.submit.assignees](/cli/config.md#spicesubmitassignees), [spice.submit.draft](/cli/config.md#spicesubmitdraft), [spice.submit.label](/cli/config.md#spicesubmitlabel), [spice.submit.label.addWhen](/cli/config.md#spicesubmitlabeladdwhen), [spice.submit.listTemplatesTimeout](/cli/config.md#spicesubmitlisttemplatestimeout), [spice.submit.navigationComment](/cli/config.md#spicesubmitnavigationcomment), [spice.submit.navigationComment.downstack](/cli/config.md#spicesubmitnavigationcommentdownstack), [spice.submit.navigationCommentStyle.marker](/cli/config.md#spicesubmitnavigationcommentstylemarker), [spice.submit.navigationCommentSync](/cli/config.md#spicesubmitnavigationcommentsync), [spice.submit.publish](/cli/config.md#spicesubmitpublish), [spice.submit.reviewers](/cli/config.md#spicesubmitreviewers), [spice.submit.reviewers.addWhen](/cli/config.md#spicesubmitreviewersaddwhen), [spice.submit.skipRestackCheck](/cli/config.md#spicesubmitskiprestackcheck), [spice.submit.template](/cli/config.md#spicesubmittemplate), [spice.submit.updateOnly](/cli/config.md#spicesubmitupdateonly), [spice.submit.web](/cli/config.md#spicesubmitweb)
 
@@ -400,6 +401,7 @@ only if there are multiple CRs in the stack.
 * `-a`, `--assign=ASSIGNEE,...`: Assign the change request to these users. Pass multiple times or separate with commas. <span class="mdx-badge"><span class="mdx-badge__icon">:material-tag:{ title="Released in version" }</span><span class="mdx-badge__text">[v0.21.0](/changelog.md#v0.21.0)</span>
 * `--no-web`: Alias for --web=false.
 * `--branch=NAME`: Branch to start at
+* `--fill-from=FILE`: JSON file mapping branch names to {title, body} for CR creation. Use '-' for stdin.
 
 **Configuration**: [spice.submit.assignees](/cli/config.md#spicesubmitassignees), [spice.submit.draft](/cli/config.md#spicesubmitdraft), [spice.submit.label](/cli/config.md#spicesubmitlabel), [spice.submit.label.addWhen](/cli/config.md#spicesubmitlabeladdwhen), [spice.submit.listTemplatesTimeout](/cli/config.md#spicesubmitlisttemplatestimeout), [spice.submit.navigationComment](/cli/config.md#spicesubmitnavigationcomment), [spice.submit.navigationComment.downstack](/cli/config.md#spicesubmitnavigationcommentdownstack), [spice.submit.navigationCommentStyle.marker](/cli/config.md#spicesubmitnavigationcommentstylemarker), [spice.submit.navigationCommentSync](/cli/config.md#spicesubmitnavigationcommentsync), [spice.submit.publish](/cli/config.md#spicesubmitpublish), [spice.submit.reviewers](/cli/config.md#spicesubmitreviewers), [spice.submit.reviewers.addWhen](/cli/config.md#spicesubmitreviewersaddwhen), [spice.submit.skipRestackCheck](/cli/config.md#spicesubmitskiprestackcheck), [spice.submit.template](/cli/config.md#spicesubmittemplate), [spice.submit.updateOnly](/cli/config.md#spicesubmitupdateonly), [spice.submit.web](/cli/config.md#spicesubmitweb)
 
@@ -555,6 +557,7 @@ only if there are multiple CRs in the stack.
 * `-a`, `--assign=ASSIGNEE,...`: Assign the change request to these users. Pass multiple times or separate with commas. <span class="mdx-badge"><span class="mdx-badge__icon">:material-tag:{ title="Released in version" }</span><span class="mdx-badge__text">[v0.21.0](/changelog.md#v0.21.0)</span>
 * `--no-web`: Alias for --web=false.
 * `--branch=NAME`: Branch to start at
+* `--fill-from=FILE`: JSON file mapping branch names to {title, body} for CR creation. Use '-' for stdin.
 
 **Configuration**: [spice.submit.assignees](/cli/config.md#spicesubmitassignees), [spice.submit.draft](/cli/config.md#spicesubmitdraft), [spice.submit.label](/cli/config.md#spicesubmitlabel), [spice.submit.label.addWhen](/cli/config.md#spicesubmitlabeladdwhen), [spice.submit.listTemplatesTimeout](/cli/config.md#spicesubmitlisttemplatestimeout), [spice.submit.navigationComment](/cli/config.md#spicesubmitnavigationcomment), [spice.submit.navigationComment.downstack](/cli/config.md#spicesubmitnavigationcommentdownstack), [spice.submit.navigationCommentStyle.marker](/cli/config.md#spicesubmitnavigationcommentstylemarker), [spice.submit.navigationCommentSync](/cli/config.md#spicesubmitnavigationcommentsync), [spice.submit.publish](/cli/config.md#spicesubmitpublish), [spice.submit.reviewers](/cli/config.md#spicesubmitreviewers), [spice.submit.reviewers.addWhen](/cli/config.md#spicesubmitreviewersaddwhen), [spice.submit.skipRestackCheck](/cli/config.md#spicesubmitskiprestackcheck), [spice.submit.template](/cli/config.md#spicesubmittemplate), [spice.submit.updateOnly](/cli/config.md#spicesubmitupdateonly), [spice.submit.web](/cli/config.md#spicesubmitweb)
 

downstack_submit.go

@@ -19,6 +19,8 @@ type downstackSubmitCmd struct {
 	submit.BatchOptions
 
 	Branch string `placeholder:"NAME" help:"Branch to start at" predictor:"trackedBranches"`
+
+	FillFrom string `name:"fill-from" help:"JSON file mapping branch names to {title, body} for CR creation. Use '-' for stdin." placeholder:"FILE"`
 }
 
 func (*downstackSubmitCmd) Help() string {
@@ -57,6 +59,14 @@ func (cmd *downstackSubmitCmd) Run(
 
 	// TODO: separate preparation of the stack from submission
 
+	if cmd.FillFrom != "" {
+		meta, err := parseFillFrom(cmd.FillFrom)
+		if err != nil {
+			return fmt.Errorf("--fill-from: %w", err)
+		}
+		cmd.BranchMetadata = meta
+	}
+
 	return submitHandler.SubmitBatch(ctx, &submit.BatchRequest{
 		Branches:     downstacks,
 		Options:      &cmd.Options,

fill_from.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"go.abhg.dev/gs/internal/handler/submit"
+)
+
+// parseFillFrom reads per-branch CR metadata from a file or stdin.
+// If path is "-", it reads from stdin.
+// The expected format is a JSON object mapping branch names
+// to objects with "title" and "body" fields.
+func parseFillFrom(path string) (map[string]submit.BranchMeta, error) {
+	var data []byte
+	var err error
+	if path == "-" {
+		data, err = io.ReadAll(os.Stdin)
+	} else {
+		data, err = os.ReadFile(path)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("read: %w", err)
+	}
+	var meta map[string]submit.BranchMeta
+	if err := json.Unmarshal(data, &meta); err != nil {
+		return nil, fmt.Errorf("parse JSON: %w", err)
+	}
+	return meta, nil
+}

internal/handler/submit/handler.go

@@ -463,6 +463,20 @@ func (l *LabelsAddWhen) UnmarshalText(bs []byte) error {
 // that are only available to batch submit operations.
 type BatchOptions struct {
 	UpdateOnlyDefault bool `config:"submit.updateOnly" help:"Default value for --update-only in batch submit operations." hidden:"" default:"false"`
+
+	// BranchMetadata provides per-branch title and body overrides
+	// for CR creation. When a branch has an entry here,
+	// its title and body are used directly
+	// instead of deriving from commits.
+	BranchMetadata map[string]BranchMeta `kong:"-"`
+}
+
+// BranchMeta holds per-branch CR metadata for batch submissions.
+// When provided via --fill-from, these values are used directly
+// instead of deriving title and body from commit messages.
+type BranchMeta struct {
+	Title string `json:"title"`
+	Body  string `json:"body"`
 }
 
 // BatchRequest is a request to submit one or more change requests.
@@ -489,10 +503,19 @@ func (h *Handler) SubmitBatch(ctx context.Context, req *BatchRequest) error {
 	for _, branch := range req.Branches {
 		// Shallow copy the options because submitBranch may modify them.
 		opts := *opts
+		sopts := &submitOptions{Options: &opts}
+
+		// Use per-branch metadata if available.
+		if batchOpts.BranchMetadata != nil {
+			if meta, ok := batchOpts.BranchMetadata[branch]; ok {
+				sopts.Title = meta.Title
+				sopts.Body = meta.Body
+			}
+		}
 		status, err := h.submitBranch(
 			ctx,
 			branch,
-			&submitOptions{Options: &opts},
+			sopts,
 		)
 		if err != nil {
 			return fmt.Errorf("submit branch %s: %w", branch, err)

stack_submit.go

@@ -14,6 +14,8 @@ import (
 type stackSubmitCmd struct {
 	submitOptions
 	submit.BatchOptions
+
+	FillFrom string `name:"fill-from" help:"JSON file mapping branch names to {title, body} for CR creation. Use '-' for stdin." placeholder:"FILE"`
 }
 
 func (*stackSubmitCmd) Help() string {
@@ -49,6 +51,14 @@ func (cmd *stackSubmitCmd) Run(
 
 	// TODO: separate preparation of the stack from submission
 
+	if cmd.FillFrom != "" {
+		meta, err := parseFillFrom(cmd.FillFrom)
+		if err != nil {
+			return fmt.Errorf("--fill-from: %w", err)
+		}
+		cmd.BranchMetadata = meta
+	}
+
 	return submitHandler.SubmitBatch(ctx, &submit.BatchRequest{
 		Branches:     toSubmit,
 		Options:      &cmd.Options,

testdata/help/downstack_submit.txt

@@ -51,6 +51,8 @@ Flags:
                                  Pass multiple times or separate with commas.
       --no-web                   Alias for --web=false.
       --branch=NAME              Branch to start at
+      --fill-from=FILE           JSON file mapping branch names to {title,
+                                 body} for CR creation. Use '-' for stdin.
 
 Global Flags:
   -h, --help           Show help for the command

testdata/help/stack_submit.txt

@@ -49,6 +49,8 @@ Flags:
   -a, --assign=ASSIGNEE,...      Assign the change request to these users.
                                  Pass multiple times or separate with commas.
       --no-web                   Alias for --web=false.
+      --fill-from=FILE           JSON file mapping branch names to {title,
+                                 body} for CR creation. Use '-' for stdin.
 
 Global Flags:
   -h, --help           Show help for the command

testdata/help/upstack_submit.txt

@@ -53,6 +53,8 @@ Flags:
                                  Pass multiple times or separate with commas.
       --no-web                   Alias for --web=false.
       --branch=NAME              Branch to start at
+      --fill-from=FILE           JSON file mapping branch names to {title,
+                                 body} for CR creation. Use '-' for stdin.
 
 Global Flags:
   -h, --help           Show help for the command

upstack_submit.go

@@ -18,6 +18,8 @@ type upstackSubmitCmd struct {
 	submit.BatchOptions
 
 	Branch string `placeholder:"NAME" help:"Branch to start at" predictor:"trackedBranches"`
+
+	FillFrom string `name:"fill-from" help:"JSON file mapping branch names to {title, body} for CR creation. Use '-' for stdin." placeholder:"FILE"`
 }
 
 func (*upstackSubmitCmd) Help() string {
@@ -78,6 +80,14 @@ func (cmd *upstackSubmitCmd) Run(
 
 	// TODO: separate preparation of the stack from submission
 
+	if cmd.FillFrom != "" {
+		meta, err := parseFillFrom(cmd.FillFrom)
+		if err != nil {
+			return fmt.Errorf("--fill-from: %w", err)
+		}
+		cmd.BranchMetadata = meta
+	}
+
 	return submitHandler.SubmitBatch(ctx, &submit.BatchRequest{
 		Branches:     upstacks,
 		Options:      &cmd.Options,