[codex] blast-radius subcommand by JordanCoin · Pull Request #71 · JordanCoin/codemap

JordanCoin · 2026-04-08T19:01:31Z

What changed

added a first-class codemap blast-radius subcommand implemented in Go
moved the built-in blast-radius defaults and output budgeting into the binary instead of a shell wrapper
removed scripts/codemap-blast-radius.sh so the CLI command is the single supported entry point
updated help text, README usage, and added integration coverage for markdown and JSON blast-radius output

Why

The blast-radius flow was still living in a shell script with jq and python3 dependencies. That made CI integration awkward and forced callers to know wrapper paths and environment defaults. This change makes codemap blast-radius the actual product surface with sensible built-in defaults and bounded output.

User impact

Callers can now use:

codemap blast-radius --ref main .
codemap blast-radius --json --ref main .
codemap blast-radius --text --ref main .

without needing the old script path or external wrapper logic.

Validation

go test ./...
manual smoke run of go run . blast-radius --ref HEAD <temp-repo>

Copilot

Pull request overview

This PR promotes “blast radius” from an external shell wrapper into a first-class Go subcommand (codemap blast-radius), consolidating defaults/output budgeting into the binary and removing the now-redundant script-based entry point.

Changes:

Added a new blast-radius subcommand implementation in Go with bounded Markdown/text/JSON output.
Refactored shared importers/ast-grep hint logic in main.go to be reused by the new subcommand.
Removed the old scripts/codemap-blast-radius.sh wrapper and updated README + tests accordingly.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
scripts/codemap-blast-radius.sh	Deleted legacy wrapper script in favor of native CLI subcommand.
README.md	Updated blast-radius usage examples to use `codemap blast-radius`.
main.go	Dispatches `blast-radius` subcommand pre global-flag parsing; refactors helper rendering/hint code usage.
main_test.go	Ensures `--help` output includes the new `blast-radius` command.
blast_radius.go	New Go implementation for bundle building, budgeting, rendering, and snippet extraction.
blast_radius_test.go	Adds integration-style coverage validating Markdown + JSON blast-radius output.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-04-08T19:07:20Z

blast_radius.go

+func blastLineMatchesTerm(line string, term blastSnippetTerm) bool {
+	switch term.Kind {
+	case "symbol":
+		pattern := regexp.MustCompile(`\b` + regexp.QuoteMeta(term.Value) + `\b`)
+		return pattern.MatchString(line)
+	default:
+		return strings.Contains(line, term.Value)
+	}


blastLineMatchesTerm recompiles a regexp for every line/term check (regexp.MustCompile inside the hot loop). This is unnecessarily expensive for large files and can dominate runtime when snippet search runs across many impacted/context files. Consider precompiling the regex once per term (e.g., store a compiled *regexp.Regexp on the term, or compile once per term iteration in findBlastRadiusSnippet) and reusing it across lines.

Copilot · 2026-04-08T19:07:20Z

blast_radius.go

+	fmt.Println("codemap blast-radius - Build a compact, bounded blast-radius bundle")
+	fmt.Println()
+	fmt.Println("Usage:")
+	fmt.Println("  codemap blast-radius [--json|--markdown|--text] [--ref <base-ref>] [path]")
+	fmt.Println()
+	fmt.Println("Examples:")
+	fmt.Println("  codemap blast-radius --ref main .")
+	fmt.Println("  codemap blast-radius --json --ref develop /path/to/repo")
+	fmt.Println()
+	fmt.Println("Flags:")
+	fs.PrintDefaults()
+	fmt.Println()
+	fmt.Println("Environment overrides:")
+	fmt.Println("  CODEMAP_BLAST_MAX_TOTAL_CHARS")
+	fmt.Println("  CODEMAP_BLAST_MAX_CHANGED_FILES")
+	fmt.Println("  CODEMAP_BLAST_MAX_AFFECTED")
+	fmt.Println("  CODEMAP_BLAST_MAX_CONTEXT")
+	fmt.Println("  CODEMAP_BLAST_MAX_SNIPPETS")
+	fmt.Println("  CODEMAP_BLAST_MAX_SNIPPETS_PER_CHANGED")
+	fmt.Println("  CODEMAP_BLAST_SNIPPET_RADIUS")
+	fmt.Println("  CODEMAP_BLAST_MAX_SNIPPET_CHARS")
+	fmt.Println("  CODEMAP_BLAST_MAX_DIFF_CHARS")
+	fmt.Println("  CODEMAP_BLAST_MAX_DEPS_CHARS")
+	fmt.Println("  CODEMAP_BLAST_MAX_IMPORTERS_CHARS")
+	fmt.Println("  CODEMAP_BLAST_MAX_IMPORTER_FILES")
+	fmt.Println("  CODEMAP_BLAST_MAX_IMPORTERS_PER_FILE")


printBlastRadiusUsage writes directly to stdout via fmt.Println, but the subcommand’s FlagSet is configured with fs.SetOutput(os.Stderr). This can split usage output across stdout/stderr (especially when Parse prints errors/usage), which is brittle for callers and tests. Consider writing usage to fs.Output() (or otherwise consistently routing help vs error output).

Suggested change

fmt.Println("codemap blast-radius - Build a compact, bounded blast-radius bundle")

fmt.Println()

fmt.Println("Usage:")

fmt.Println(" codemap blast-radius [--json|--markdown|--text] [--ref <base-ref>] [path]")

fmt.Println()

fmt.Println("Examples:")

fmt.Println(" codemap blast-radius --ref main .")

fmt.Println(" codemap blast-radius --json --ref develop /path/to/repo")

fmt.Println()

fmt.Println("Flags:")

fs.PrintDefaults()

fmt.Println()

fmt.Println("Environment overrides:")

fmt.Println(" CODEMAP_BLAST_MAX_TOTAL_CHARS")

fmt.Println(" CODEMAP_BLAST_MAX_CHANGED_FILES")

fmt.Println(" CODEMAP_BLAST_MAX_AFFECTED")

fmt.Println(" CODEMAP_BLAST_MAX_CONTEXT")

fmt.Println(" CODEMAP_BLAST_MAX_SNIPPETS")

fmt.Println(" CODEMAP_BLAST_MAX_SNIPPETS_PER_CHANGED")

fmt.Println(" CODEMAP_BLAST_SNIPPET_RADIUS")

fmt.Println(" CODEMAP_BLAST_MAX_SNIPPET_CHARS")

fmt.Println(" CODEMAP_BLAST_MAX_DIFF_CHARS")

fmt.Println(" CODEMAP_BLAST_MAX_DEPS_CHARS")

fmt.Println(" CODEMAP_BLAST_MAX_IMPORTERS_CHARS")

fmt.Println(" CODEMAP_BLAST_MAX_IMPORTER_FILES")

fmt.Println(" CODEMAP_BLAST_MAX_IMPORTERS_PER_FILE")

var out io.Writer = fs.Output()

if out == nil {

out = os.Stderr

}

fmt.Fprintln(out, "codemap blast-radius - Build a compact, bounded blast-radius bundle")

fmt.Fprintln(out)

fmt.Fprintln(out, "Usage:")

fmt.Fprintln(out, " codemap blast-radius [--json|--markdown|--text] [--ref <base-ref>] [path]")

fmt.Fprintln(out)

fmt.Fprintln(out, "Examples:")

fmt.Fprintln(out, " codemap blast-radius --ref main .")

fmt.Fprintln(out, " codemap blast-radius --json --ref develop /path/to/repo")

fmt.Fprintln(out)

fmt.Fprintln(out, "Flags:")

fs.PrintDefaults()

fmt.Fprintln(out)

fmt.Fprintln(out, "Environment overrides:")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_TOTAL_CHARS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_CHANGED_FILES")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_AFFECTED")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_CONTEXT")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_SNIPPETS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_SNIPPETS_PER_CHANGED")

fmt.Fprintln(out, " CODEMAP_BLAST_SNIPPET_RADIUS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_SNIPPET_CHARS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_DIFF_CHARS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_DEPS_CHARS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_IMPORTERS_CHARS")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_IMPORTER_FILES")

fmt.Fprintln(out, " CODEMAP_BLAST_MAX_IMPORTERS_PER_FILE")

Copilot · 2026-04-08T19:07:20Z

blast_radius.go

+	fs.BoolVar(&markdownMode, "markdown", false, "Emit Markdown output (default)")
+	fs.BoolVar(&markdownMode, "md", false, "Emit Markdown output (default)")


The --markdown/--md flags are labeled as “default”, but their default value is false and Markdown is emitted even when the flags are omitted. This makes --markdown redundant and can confuse users reading PrintDefaults() output. Consider removing --markdown/--md and treating Markdown as the implicit default, or replacing the three booleans with a single --format flag defaulting to markdown.

Suggested change

fs.BoolVar(&markdownMode, "markdown", false, "Emit Markdown output (default)")

fs.BoolVar(&markdownMode, "md", false, "Emit Markdown output (default)")

fs.BoolVar(&markdownMode, "markdown", false, "Emit Markdown output")

fs.BoolVar(&markdownMode, "md", false, "Emit Markdown output")

Copilot · 2026-04-08T19:07:21Z

blast_radius.go

+	if isGitHubURL(root) && localErr != nil {
+		repoName := extractRepoName(root)
+		tempDir, err := cloneRepo(root, repoName)
+		if err != nil {
+			return "", cleanup, err
+		}
+		cleanup = func() { _ = os.RemoveAll(tempDir) }
+		root = tempDir


resolveBlastRadiusRoot clones when os.Stat(root) returns any error (localErr != nil). That includes non-"not exist" errors (e.g., permission denied), which can unexpectedly trigger a network clone and ignore an existing local path. Consider only cloning when os.IsNotExist(localErr) is true, and otherwise return the stat error to the caller.

Suggested change

if isGitHubURL(root) && localErr != nil {

repoName := extractRepoName(root)

tempDir, err := cloneRepo(root, repoName)

if err != nil {

return "", cleanup, err

}

cleanup = func() { _ = os.RemoveAll(tempDir) }

root = tempDir

if isGitHubURL(root) {

if os.IsNotExist(localErr) {

repoName := extractRepoName(root)

tempDir, err := cloneRepo(root, repoName)

if err != nil {

return "", cleanup, err

}

cleanup = func() { _ = os.RemoveAll(tempDir) }

root = tempDir

} else if localErr != nil {

return "", cleanup, localErr

}

chatgpt-codex-connector

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: dbf8d83ab3

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

Open a pull request for review
Mark a draft as ready
Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

chatgpt-codex-connector · 2026-04-08T19:10:20Z

blast_radius.go

+		} else {
+			fmt.Fprintf(os.Stderr, "Error building blast radius: %v\n", err)
+		}
+		os.Exit(1)


Avoid os.Exit after deferring remote clone cleanup

When root is a remote URL, resolveBlastRadiusRoot clones into a temp directory and defer cleanup() is set, but this error path calls os.Exit(1), which skips deferred functions. In runs where bundle construction fails (for example invalid --ref or missing ast-grep with changed files), each invocation leaks a temp clone on disk instead of removing it.

Useful? React with 👍 / 👎.

chatgpt-codex-connector · 2026-04-08T19:10:20Z

blast_radius.go

+func blastLineMatchesTerm(line string, term blastSnippetTerm) bool {
+	switch term.Kind {
+	case "symbol":
+		pattern := regexp.MustCompile(`\b` + regexp.QuoteMeta(term.Value) + `\b`)


Precompile symbol-match regex outside the line loop

findBlastRadiusSnippet checks every line of candidate files, and for symbol terms it calls blastLineMatchesTerm per line; that helper recompiles the same regex every call via regexp.MustCompile. On large files or many snippet candidates this creates thousands of unnecessary compilations and can materially slow blast-radius generation.

Useful? React with 👍 / 👎.

blast-radius subcommand

dbf8d83

JordanCoin marked this pull request as ready for review April 8, 2026 19:03

Copilot AI review requested due to automatic review settings April 8, 2026 19:03

Copilot started reviewing on behalf of JordanCoin April 8, 2026 19:03 View session

Copilot AI reviewed Apr 8, 2026

View reviewed changes

chatgpt-codex-connector bot reviewed Apr 8, 2026

View reviewed changes

address blast-radius review feedback

99ee06b

JordanCoin merged commit 8e0735c into main Apr 8, 2026
12 checks passed

JordanCoin deleted the codex/blast-radius-cli branch April 8, 2026 19:17

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[codex] blast-radius subcommand#71

[codex] blast-radius subcommand#71
JordanCoin merged 2 commits intomainfrom
codex/blast-radius-cli

JordanCoin commented Apr 8, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Apr 8, 2026

Uh oh!

Copilot AI Apr 8, 2026

Uh oh!

Copilot AI Apr 8, 2026

Uh oh!

Copilot AI Apr 8, 2026

Uh oh!

chatgpt-codex-connector bot left a comment

Uh oh!

chatgpt-codex-connector bot Apr 8, 2026

Uh oh!

chatgpt-codex-connector bot Apr 8, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

		fs.BoolVar(&markdownMode, "markdown", false, "Emit Markdown output (default)")
		fs.BoolVar(&markdownMode, "md", false, "Emit Markdown output (default)")

Conversation

JordanCoin commented Apr 8, 2026

What changed

Why

User impact

Validation

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

chatgpt-codex-connector bot left a comment

Choose a reason for hiding this comment

💡 Codex Review

Uh oh!

chatgpt-codex-connector bot Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

chatgpt-codex-connector bot Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants