Add some checks to ensure that the matched substring matches the expectations, thereby avoiding potential errors

[zengwei00]

…ctations, thereby avoiding potential errors

PR Checklist

PR Structure

• This PR has reasonably narrow scope (if not, break it down into smaller PRs).
• This PR avoids mixing refactoring changes with feature changes (split into two PRs
  otherwise).
• This PR's title starts with name of package that is most changed in the PR, ex.
  services/friendbot, or all or doc if the changes are broad or impact many
  packages.

Thoroughness

• This PR adds tests for the most critical parts of the new functionality or fixes.
• I've updated any docs (developer docs, .md
  files, etc... affected by this change). Take a look in the docs folder for a given service,
  like this one.

Release planning

• I've updated the relevant CHANGELOG (here for Horizon) if
  needed with deprecations, added features, breaking changes, and DB schema changes.
• I've decided if this PR requires a new major/minor version according to
  semver, or if it's mainly a patch change. The PR is targeted at the next
  release branch if it's not a patch change.

What

[TODO: Short statement about what is changing.]
Add two checks to help prevent erroneous data from being passed on to other parts and ensure necessary data validation is carried out before performing subsequent operations

Why

[TODO: Why this change is being made. Include any context required to understand the why.]

Known limitations

[TODO or N/A]

[mollykarcher]

Can you please fill out the PR description and articulate what exactly the issue is that you're experiencing, how you've solved it, and any other context you think is relevant? Thanks!

[zengwei00]

Can you please fill out the PR description and articulate what exactly the issue is that you're experiencing, how you've solved it, and any other context you think is relevant? Thanks!

Add two checks to help prevent erroneous data from being passed on to other parts and ensure necessary data validation is carried out before performing subsequent operations

[zengwei00]

@mollykarcher