fix: support feature branch numbers with 4+ digits by t-sakoda · Pull Request #2040 · github/spec-kit

t-sakoda · 2026-04-01T05:53:46Z

Description

The sequential feature number regex in common.sh and common.ps1 was hardcoded to exactly 3 digits ({3}), causing branches like 1234-feature-name to be rejected once a project exceeds 999 features.

This PR changes the pattern to {3,} (3 or more digits) so that 4+ digit prefixes are recognized correctly. A guard is also added in check_feature_branch / Test-FeatureBranch to prevent malformed timestamps (e.g. 2026031-143022-feat) from being falsely accepted as sequential prefixes.

Closes #344

Testing

Tested locally with uv run specify --help
Ran existing tests with uv sync && uv run pytest
Tested with a sample project (if applicable)

All 27 test_timestamp_branches.py tests pass, including the existing test that rejects partial timestamps.

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I did use AI assistance (describe below)

Code changes generated and reviewed with Claude Code (Claude Opus 4.6).

…ommon.ps1 The sequential feature number pattern was hardcoded to exactly 3 digits (`{3}`), causing branches like `1234-feature-name` to be rejected. Changed to `{3,}` (3 or more digits) to support growing projects. Also added a guard to exclude malformed timestamp patterns from being accepted as sequential prefixes. Closes github#344 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Copilot

Pull request overview

Updates feature-branch parsing in Spec Kit’s Bash and PowerShell helper scripts to support sequential prefixes beyond 999 (3+ digits) while preventing malformed timestamp-like prefixes from being treated as sequential.

Changes:

Allow sequential feature prefixes with 3+ digits ({3,}) when scanning specs/ and resolving feature directories.
Update feature-branch validation to accept 4+ digit sequential prefixes.
Add a guard intended to reject malformed timestamp-like branches (e.g., 2026031-143022-feat) from being accepted as sequential.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
scripts/powershell/common.ps1	Expands sequential prefix matching and adds a timestamp-shape guard in `Test-FeatureBranch`.
scripts/bash/common.sh	Expands sequential prefix matching, updates prefix-based directory resolution, and adds the same timestamp-shape guard in `check_feature_branch`.

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Copilot · 2026-04-01T05:59:04Z

scripts/powershell/common.ps1

+            } elseif ($_.Name -match '^(\d{3,})-') {
                $num = [int]$matches[1]
                if ($num -gt $highest) {


In Get-CurrentBranch, the sequential prefix is now 3+ digits, but $num = [int]$matches[1] can throw for larger values (e.g., external ticket IDs or very large feature numbers > 2,147,483,647), breaking the non-git fallback branch detection. Consider switching to [long] (or [long]::TryParse) to match the approach used in scripts/powershell/create-new-feature.ps1 and avoid overflow exceptions.

Fixed in ab7c3c1 — changed [int] to [long] to prevent overflow for large feature numbers.

Copilot · 2026-04-01T05:59:05Z

scripts/powershell/common.ps1

+    # Accept sequential prefix (3+ digits) but exclude malformed timestamps (digits-6digits pattern)
+    $isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]+-[0-9]{6}-')


The new malformed-timestamp guard ($Branch -notmatch '^[0-9]+-[0-9]{6}-') also rejects otherwise-valid sequential branches where the slug starts with 6 digits (e.g., 004-123456-fix-bug). If the intent is only to reject partial timestamps like 2026031-143022-feat, narrow the exclusion pattern (for example, only the 7-digit-date case) so numeric-leading slugs remain valid.

Suggested change

# Accept sequential prefix (3+ digits) but exclude malformed timestamps (digits-6digits pattern)

$isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]+-[0-9]{6}-')

# Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time)

$isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]{7}-[0-9]{6}-')

Fixed in ab7c3c1 — narrowed the pattern to ^[0-9]{7}-[0-9]{6}- so only the 7-digit-date + 6-digit-time shape is excluded.

Copilot · 2026-04-01T05:59:05Z

scripts/bash/common.sh

+    # Accept sequential prefix (3+ digits) but exclude malformed timestamps (digits-6digits pattern)
+    local is_sequential=false
+    if [[ "$branch" =~ ^[0-9]{3,}- ]] && [[ ! "$branch" =~ ^[0-9]+-[0-9]{6}- ]]; then


The malformed-timestamp exclusion ([[ ! "$branch" =~ ^[0-9]+-[0-9]{6}- ]]) is broad enough to reject valid sequential branches whose slug starts with 6 digits (e.g., 004-123456-fix-bug). If the goal is specifically to block partial timestamps like 2026031-143022-feat, consider narrowing this pattern (e.g., target only the 7-digit-date + 6-digit-time shape) so numeric-leading slugs are still accepted.

Suggested change

# Accept sequential prefix (3+ digits) but exclude malformed timestamps (digits-6digits pattern)

local is_sequential=false

if [[ "$branch" =~ ^[0-9]{3,}- ]] && [[ ! "$branch" =~ ^[0-9]+-[0-9]{6}- ]]; then

# Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time pattern)

local is_sequential=false

if [[ "$branch" =~ ^[0-9]{3,}- ]] && [[ ! "$branch" =~ ^[0-9]{7}-[0-9]{6}- ]]; then

Fixed in ab7c3c1 — same narrowing applied here: ^[0-9]{7}-[0-9]{6}-.

- Change [int] to [long] in PowerShell Get-CurrentBranch to avoid overflow for large feature numbers (>2,147,483,647) - Narrow malformed-timestamp exclusion from ^[0-9]+-[0-9]{6}- to ^[0-9]{7}-[0-9]{6}- so valid sequential branches like 004-123456-fix-bug are not rejected Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Copilot

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

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Copilot · 2026-04-01T06:33:28Z

scripts/bash/common.sh

+    # Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time)
+    local is_sequential=false
+    if [[ "$branch" =~ ^[0-9]{3,}- ]] && [[ ! "$branch" =~ ^[0-9]{7}-[0-9]{6}- ]]; then
+        is_sequential=true
+    fi
+    if [[ "$is_sequential" != "true" ]] && [[ ! "$branch" =~ ^[0-9]{8}-[0-9]{6}- ]]; then
        echo "ERROR: Not on a feature branch. Current branch: $branch" >&2
-        echo "Feature branches should be named like: 001-feature-name or 20260319-143022-feature-name" >&2
+        echo "Feature branches should be named like: 001-feature-name, 1234-feature-name, or 20260319-143022-feature-name" >&2
        return 1


check_feature_branch now accepts sequential prefixes with 4+ digits, but the existing tests for check_feature_branch only cover a 3-digit sequential branch (004-feat). Add a regression test that asserts check_feature_branch "1234-feat" "true" succeeds, so the new {3,} behavior is covered directly (separate from create-new-feature.sh tests).

Fixed in 49c29c2 — added test_accepts_four_digit_sequential_branch that asserts check_feature_branch "1234-feat" "true" succeeds.

Copilot · 2026-04-01T06:33:28Z

scripts/bash/common.sh

    local prefix=""
    if [[ "$branch_name" =~ ^([0-9]{8}-[0-9]{6})- ]]; then
        prefix="${BASH_REMATCH[1]}"
-    elif [[ "$branch_name" =~ ^([0-9]{3})- ]]; then
+    elif [[ "$branch_name" =~ ^([0-9]{3,})- ]]; then
        prefix="${BASH_REMATCH[1]}"


find_feature_dir_by_prefix now accepts 4+ digit sequential prefixes (^([0-9]{3,})-), but the existing TestFindFeatureDirByPrefix cases only cover timestamp prefixes. Add a test that creates something like specs/1000-original and asserts that find_feature_dir_by_prefix <repo> "1000-different" resolves to the existing 1000-... directory, so the new {3,} path is covered.

Fixed in 49c29c2 — added test_four_digit_sequential_prefix that creates specs/1000-original-feat and asserts find_feature_dir_by_prefix resolves 1000-different-name to it.

Cover check_feature_branch and find_feature_dir_by_prefix with 4-digit sequential prefixes, as requested in PR review github#2040. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

tests/test_timestamp_branches.py:197

There’s test coverage for rejecting a 7-digit partial date (2026031-143022-feat), but no regression test for the newly-possible case 20260319-143022 (8-digit date + 6-digit time with no final -<slug>). Adding a test that asserts check_feature_branch "20260319-143022" "true" fails would lock in the intended malformed-timestamp guard while still allowing 4+ digit sequential branches.

    def test_accepts_four_digit_sequential_branch(self):
        """check_feature_branch accepts 4+ digit sequential branch."""
        result = source_and_call('check_feature_branch "1234-feat" "true"')
        assert result.returncode == 0

    def test_rejects_partial_timestamp(self):
        """Test 9: check_feature_branch rejects 7-digit date."""
        result = source_and_call('check_feature_branch "2026031-143022-feat" "true"')
        assert result.returncode != 0

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Copilot · 2026-04-01T11:47:16Z

scripts/bash/common.sh

+    # Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time)
+    local is_sequential=false
+    if [[ "$branch" =~ ^[0-9]{3,}- ]] && [[ ! "$branch" =~ ^[0-9]{7}-[0-9]{6}- ]]; then
+        is_sequential=true
+    fi
+    if [[ "$is_sequential" != "true" ]] && [[ ! "$branch" =~ ^[0-9]{8}-[0-9]{6}- ]]; then


With the sequential regex widened to {3,}, branches like 20260319-143022 (8-digit date + 6-digit time but missing the final -<slug> segment) now match the sequential check and will be accepted. This seems to undermine the intent of rejecting malformed timestamps; consider explicitly rejecting ^\d{8}-\d{6}$ / ^\d{8}-\d{6}[^-] (and the analogous 7-digit case) before treating the branch as sequential.

Copilot · 2026-04-01T11:47:17Z

scripts/powershell/common.ps1

+    # Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time)
+    $isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]{7}-[0-9]{6}-')
+    if (-not $isSequential -and $Branch -notmatch '^\d{8}-\d{6}-') {


Because sequential validation now allows 3+ digits, a branch named 20260319-143022 (looks like a timestamp but lacks the trailing -<name>) matches $isSequential and will be accepted. If malformed timestamps should be rejected, add an explicit check for the ^\d{8}-\d{6}$ / missing-third-segment shape (and optionally the 7-digit date variant) so these don’t slip through as “sequential”.

Suggested change

# Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time)

$isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]{7}-[0-9]{6}-')

if (-not $isSequential -and $Branch -notmatch '^\d{8}-\d{6}-') {

# Accept sequential prefix (3+ digits) but exclude malformed timestamps

# Valid timestamp-based feature branches look like: YYYYMMDD-HHMMSS-feature-name

$hasValidTimestampPrefix = ($Branch -match '^\d{8}-\d{6}-')

# Malformed timestamps: date+time with no trailing "-<name>" (optionally 7-digit date variant)

$hasMalformedTimestamp = ($Branch -match '^(?:\d{7}|\d{8})-\d{6}$')

$isSequential = ($Branch -match '^[0-9]{3,}-') -and (-not $hasMalformedTimestamp)

if (-not $isSequential -and -not $hasValidTimestampPrefix) {

mnriem

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Copilot AI review requested due to automatic review settings April 1, 2026 05:53

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t-sakoda marked this pull request as ready for review April 1, 2026 06:29

t-sakoda requested a review from mnriem as a code owner April 1, 2026 06:29

Copilot AI review requested due to automatic review settings April 1, 2026 06:29

Copilot started reviewing on behalf of t-sakoda April 1, 2026 06:29 View session

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test: add regression tests for 4+ digit feature branch support

49c29c2

Cover check_feature_branch and find_feature_dir_by_prefix with 4-digit sequential prefixes, as requested in PR review github#2040. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mnriem requested a review from Copilot April 1, 2026 11:43

Copilot started reviewing on behalf of mnriem April 1, 2026 11:43 View session

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mnriem requested changes Apr 1, 2026

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		# Accept sequential prefix (3+ digits) but exclude malformed timestamps (digits-6digits pattern)
		$isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]+-[0-9]{6}-')

-    # Accept sequential prefix (3+ digits) but exclude malformed timestamps (7-digit date + 6-digit time)
-    $isSequential = ($Branch -match '^[0-9]{3,}-') -and ($Branch -notmatch '^[0-9]{7}-[0-9]{6}-')
-    if (-not $isSequential -and $Branch -notmatch '^\d{8}-\d{6}-') {
+    # Accept sequential prefix (3+ digits) but exclude malformed timestamps
+    # Valid timestamp-based feature branches look like: YYYYMMDD-HHMMSS-feature-name
+    $hasValidTimestampPrefix = ($Branch -match '^\d{8}-\d{6}-')
+    # Malformed timestamps: date+time with no trailing "-<name>" (optionally 7-digit date variant)
+    $hasMalformedTimestamp = ($Branch -match '^(?:\d{7}|\d{8})-\d{6}$')
+    $isSequential = ($Branch -match '^[0-9]{3,}-') -and (-not $hasMalformedTimestamp)
+    if (-not $isSequential -and -not $hasValidTimestampPrefix) {

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t-sakoda commented Apr 1, 2026 •

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