Add --what-if option to prepare-release command for simulating version changes by Copilot · Pull Request #1242 · dotnet/Nerdbank.GitVersioning

Copilot · 2025-08-10T19:02:10Z

This PR adds a --what-if option to the nbgv prepare-release command that allows users to simulate the prepare-release operation and see what versions would be set without actually making any git changes.

What it does

The --what-if flag enables users to preview the results of a prepare-release operation before committing to it:

# See what versions would be set with default settings
nbgv prepare-release --what-if

# Preview with custom version increment
nbgv prepare-release --what-if --versionIncrement Major

# Get machine-readable JSON output
nbgv prepare-release --what-if --format json

Implementation

New --what-if option: Added to the prepare-release command with appropriate help text
SimulatePrepareRelease method: New method in ReleaseManager that performs all the same validation and version calculation logic as the regular PrepareRelease method, but without making any git changes
Consistent validation: The what-if mode uses the exact same validation logic, so errors and warnings are identical to the regular mode
Output formats: Supports both human-readable text output (with "What-if:" prefixes) and machine-readable JSON output
Comprehensive testing: Added 12 new tests covering various scenarios including version increments, prerelease tags, error conditions, and edge cases

Example outputs

Text format:

What-if: v3.8 branch would track v3.8 stabilization and release.
What-if: main branch would track v3.9-alpha development.

JSON format:

{
  "CurrentBranch": {
    "Name": "main",
    "Commit": "abc123...",
    "Version": "3.9-alpha"
  },
  "NewBranch": {
    "Name": "v3.8",
    "Commit": "abc123...",
    "Version": "3.8"
  }
}

This enhancement provides a safe way for users to understand the impact of prepare-release operations before executing them, addressing the need for predictable version management workflows.

Fixes #1019.

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Co-authored-by: AArnott <[email protected]>

…nd remove Array.Empty arguments Co-authored-by: AArnott <[email protected]>

Updated [Nerdbank.GitVersioning](https://github.com/dotnet/Nerdbank.GitVersioning) from 3.9.50 to 3.10.91. <details> <summary>Release notes</summary> _Sourced from [Nerdbank.GitVersioning's releases](https://github.com/dotnet/Nerdbank.GitVersioning/releases)._ ## 3.10.91 ## What's Changed * Retry file operations on access denied errors by @AArnott in dotnet/Nerdbank.GitVersioning#1408 **Full Changelog**: dotnet/Nerdbank.GitVersioning@v3.10.85...v3.10.91 ## 3.10.85 ## What's Changed * Avoid writing server.json multiple times in a single pack by @AArnott in dotnet/Nerdbank.GitVersioning#1391 **Full Changelog**: dotnet/Nerdbank.GitVersioning@v3.10.70...v3.10.85 ## 3.10.70 ## What's Changed ### Fixes * Fix case insensitivity for the managed engine on git worktrees, and implement for libgit2 by @AArnott in dotnet/Nerdbank.GitVersioning#1334 * Fix native heap corruption in GitPackIndexMappedReaderTests by @AArnott in dotnet/Nerdbank.GitVersioning#1360 ### Enhancements * Add prerelease property to inheriting version.json files by @Copilot in dotnet/Nerdbank.GitVersioning#1317 * Add NBGV_SetCloudBuildVersionVars property to disable cloud build variable output by @Copilot in dotnet/Nerdbank.GitVersioning#1324 * Add --what-if option to prepare-release command for simulating version changes by @Copilot in dotnet/Nerdbank.GitVersioning#1242 * Build nbgv CLI tool for .NET 9 and 10 by @AArnott in dotnet/Nerdbank.GitVersioning#1369 **Full Changelog**: dotnet/Nerdbank.GitVersioning@v3.9.50...v3.10.70 ## 3.10.44-alpha ## What's Changed ### Fixes * Fix case insensitivity for the managed engine on git worktrees, and implement for libgit2 by @AArnott in dotnet/Nerdbank.GitVersioning#1334 ### Enhancements * Add --what-if option to prepare-release command for simulating version changes by @Copilot in dotnet/Nerdbank.GitVersioning#1242 * Add NBGV_SetCloudBuildVersionVars property to disable cloud build variable output by @Copilot in dotnet/Nerdbank.GitVersioning#1324 ### Dependency updates * chore(deps): update dependency microsoft.build.locator to 1.11.2 by @renovate[bot] in dotnet/Nerdbank.GitVersioning#1304 * chore(deps): update dotnet monorepo by @renovate[bot] in dotnet/Nerdbank.GitVersioning#1309 * Update dotnet monorepo by @renovate[bot] in dotnet/Nerdbank.GitVersioning#1338 **Full Changelog**: dotnet/Nerdbank.GitVersioning@v3.10.8-alpha...v3.10.44-alpha ## 3.10.8-alpha ## What's Changed * Add prerelease property to inheriting version.json files by @Copilot in dotnet/Nerdbank.GitVersioning#1317 **Full Changelog**: dotnet/Nerdbank.GitVersioning@v3.9.50...v3.10.8-alpha Commits viewable in [compare view](dotnet/Nerdbank.GitVersioning@v3.9.50...v3.10.91). </details> [![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=Nerdbank.GitVersioning&package-manager=nuget&previous-version=3.9.50&new-version=3.10.91)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- <details> <summary>Dependabot commands and options</summary> <br /> You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot show <dependency name> ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself) </details>

Initial plan

d6eba4a

Copilot AI assigned Copilot and AArnott Aug 10, 2025

Copilot started work on behalf of AArnott August 10, 2025 19:02 View session

Copilot AI and others added 2 commits August 10, 2025 19:13

Add --what-if option to prepare-release command

49e89ab

Co-authored-by: AArnott <[email protected]>

Add comprehensive tests for SimulatePrepareRelease functionality

407eb5a

Co-authored-by: AArnott <[email protected]>

AArnott requested changes Aug 10, 2025

View reviewed changes

Comment thread src/NerdBank.GitVersioning/ReleaseManager.cs Outdated

Comment thread src/nbgv/Program.cs Outdated

Fix StyleCop warnings and reorganize WriteToOutput method

c5a8605

Co-authored-by: AArnott <[email protected]>

Copilot AI changed the title ~~[WIP] Simulate the future version~~ Add --what-if option to prepare-release command for simulating version changes Aug 10, 2025

Copilot AI requested a review from AArnott August 10, 2025 19:31

Copilot finished work on behalf of AArnott August 10, 2025 19:31

Copilot started work on behalf of AArnott August 10, 2025 19:31 View session

Refactor PrepareRelease to use unified method with whatIf parameter a…

28d04ed

…nd remove Array.Empty arguments Co-authored-by: AArnott <[email protected]>

Copilot finished work on behalf of AArnott August 10, 2025 19:49

AArnott added 2 commits December 20, 2025 16:07

touch-ups

02f992d

Merge remote-tracking branch 'origin/main' into copilot/fix-1019

387167b

AArnott marked this pull request as ready for review December 20, 2025 23:10

AArnott enabled auto-merge December 20, 2025 23:11

AArnott approved these changes Dec 20, 2025

View reviewed changes

AArnott added this pull request to the merge queue Dec 20, 2025

Merged via the queue into main with commit e1a9804 Dec 20, 2025
12 checks passed

AArnott deleted the copilot/fix-1019 branch December 20, 2025 23:57

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Add --what-if option to prepare-release command for simulating version changes#1242

Add --what-if option to prepare-release command for simulating version changes#1242
AArnott merged 7 commits into
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Copilot AI commented Aug 10, 2025 •

edited

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Copilot AI commented Aug 10, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Copilot AI commented Aug 10, 2025 •

edited

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