Managing VBA's Case-Change Chaos: The 80/20 Approach to Smoother Access Version Control

Anyone developing in Microsoft Access who uses version control has encountered this maddening quirk: the VBA IDE's automatic and global identifier casing changes that wreak havoc on your version control history. This behavior turns simple edits into cascades of file changes—most of which are just cosmetic letter case shifts rather than meaningful code updates.

This article presents a practical, generalizable idea—an 80/20 approach—for mitigating the impact of VBA's case-changing "feature" on Access version control workflows.

This concept applies regardless of the specific tools you use, whether it's a homegrown script, the open-source msaccess-vcs-addin, commercial tools like Ivercy or OASIS-SVN, or Microsoft's own upcoming version control integration.

The Core Problem: VBA's Global Casing Enforcement

As I described in my article VBA's Case Changing "Feature", the VBA IDE enforces a global rule: when you change the casing of an identifier anywhere in your project, the IDE immediately applies that casing everywhere else—irrespective of scope, module, or identifier type.

While this helps avoid confusion in a case-insensitive language, it wreaks havoc on text-based version control systems. These systems treat letter case changes as actual code changes, flooding your diffs and commit logs with noise.

Why Version Control Systems Struggle with VBA's Case Changes

Version control systems like Git or Mercurial rely on detecting meaningful differences between file versions. However, with VBA's behavior:

Simple changes to the casing of a variable or method name cause many unrelated files to appear modified.
Commits become cluttered with changes that don't affect functionality.
Reviewing diffs and merges becomes more error-prone and time-consuming.
Developers waste time identifying real changes amid false alarms.

The 80/20 Concept: Ignore Case-Only Differences in Version Control Workflows

The key insight from my years of experience is this: when determining whether a file has changed for version control purposes, ignore differences that are solely due to letter casing.

This doesn't mean ignoring all casing changes blindly—only those files where the sole difference is uppercase vs. lowercase letters.

How This Concept Works in Practice

When comparing exported source files against the repository, convert both versions of the file content to all lowercase (or all uppercase).
Compare these normalized versions to detect real changes.
If they match, discard the change as a false positive caused by case shifts.
If they differ beyond casing, treat it as a real change and commit accordingly.

This approach drastically reduces noise in version control, making it easier to focus on actual code edits.

My Solution: A 15-Year-Trusted AutoHotkey Script

For over 15 years, I've relied on a simple yet effective AutoHotkey script that integrates with Mercurial commands to implement this 80/20 approach in my daily workflow. It:

Detects which files' only changes are letter case differences.
Automatically reverts those changes before committing.
Keeps my repositories clean and focused on meaningful edits.

This script has been battle-tested across dozens of active Access projects, saving countless hours spent chasing phantom changes.

Exploring a Proof of Concept Implementation in msaccess-vcs-addin

To demonstrate how the 80/20 concept of ignoring case-only differences can be practically implemented in an Access version control tool, I have detailed a proof of concept within the context of the open-source msaccess-vcs-addin project. This exploration is documented extensively in my GitHub issue #599 and discussed further in discussion #624.

The core idea is to adjust the file change detection mechanism by modifying the hashing algorithm that determines whether an exported Access object’s source file has changed compared to the repository version. Instead of hashing the raw file contents as-is, the proof of concept introduces a step to normalize the text by converting it to a uniform case (e.g., all lowercase) before hashing. This allows the version control add-in to treat files that differ only by letter casing as identical, thereby preventing unnecessary exports and commits triggered solely by VBA’s case-changing behavior.

Key Implementation Details:

Hashing Adjustment:
The checksum calculation function is altered to preprocess the file content by converting the entire text to lowercase before computing the hash. This means that "MyVariable" and "myvariable" produce the same hash, avoiding false-positive detection of changes.
Selective Application:
This case-insensitive hashing can be made optional or opt-in, ensuring backward compatibility and allowing users to enable it only if desired.
No Alteration of Exported Files:
Importantly, the actual files exported from Access are left unchanged in terms of casing. The normalization affects only the internal comparison process, preserving the original code formatting.
Integration Points:
The modification touches the IDbComponent_IsModified methods within key classes such as clsDbForm, clsDbModule, and clsDbReport, where file content comparisons decide if a re-export is necessary.

This approach provides a concrete example of how the 80/20 solution can be integrated into an existing version control workflow, distinct from my longstanding AutoHotkey script, and illustrates its feasibility and minimal invasiveness. While this particular implementation is within msaccess-vcs-addin, the concept is flexible enough to be adapted to other Access version control tools or custom workflows.

Why Microsoft Won't Fix This (Anytime Soon)

I've raised this issue directly with the Access team at both Access DevCon Vienna 2025 and the Microsoft MVP Summit. Unfortunately:

The Access team does not control the VBA IDE's internal casing logic.
Nobody at Microsoft currently wants to modify this part of the VBA IDE.
The Access team themselves don't write VBA code daily, so they underestimate the extent of the problem.
This means the root cause is unlikely to be fixed in the near future.

Until Microsoft addresses the VBA IDE casing behavior directly, the 80/20 approach remains the most practical workaround.

Summary

Case sensitivity in VBA source control is a surprisingly persistent challenge.

VBA’s Integrated Development Environment (IDE) automatically changes the letter casing of identifiers globally, resulting in many false-positive changes in version control systems. These false positives are more than just annoying—they obscure true positives, such as accidental or meaningful code changes, making it harder to identify real issues. Since Microsoft shows little indication of fixing this behavior, I have found that using case-insensitive comparisons on exported source files is an effective way to dramatically reduce noisy, irrelevant diffs. This approach helps maintain cleaner commit histories and improves the core strength of version control: clearly identifying meaningful changes.

By adopting case-insensitive change detection, developers save time and can better focus on genuine code modifications rather than misleading version control noise.