fix(sdk): detect character pattern wildcards in View instrument_name (#5664)

[somuai]

Description

Fixes #5664

According to the OpenTelemetry Metrics Specification for Views (https://opentelemetry.io/docs/specs/otel/metrics/sdk/#view):

"If name is provided, the View MUST match at most one instrument. If instrument_name contains wildcard characters (*, ?, [seq], [!seq]), name MUST NOT be provided."

Previously, View.__init__ checked for wildcard characters in instrument_name only by inspecting whether "*" in instrument_name or "?" in instrument_name. However, instrument matching in View._match is executed via fnmatch.fnmatchcase(), which supports character sequence wildcards such as [seq] and [!seq] (for example, instrument_name="http_[0-9]"). Because brackets were not checked, specifying a character set wildcard alongside a custom name bypassed the validation check, permitting multiple instruments to match a single renamed View stream in violation of the specification constraint.

This change updates View.__init__ to detect character pattern wildcards ("[", "]") in instrument_name in addition to "*" and "?", raising an exception whenever name is provided with any wildcard pattern.

Changes

• In opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/view.py:
  • Update View.__init__ wildcard check to verify any(c in instrument_name for c in "*?[]").
• In opentelemetry-sdk/tests/metrics/test_view.py:
  • Expand test_view_name with subtests covering *, ?, [0-9], [!a-z], [abc], [, and ], verifying they raise an exception when name is provided.
  • Verify that a valid non-wildcard instrument_name succeeds with name.
• Add .changelog/5664.fixed.

Verification

• Ran unit tests locally:
  PYTHONPATH=opentelemetry-api/src:opentelemetry-sdk/src:opentelemetry-semantic-conventions/src:tests/opentelemetry-test-utils/src pytest opentelemetry-sdk/tests/metrics/test_view.py opentelemetry-sdk/tests/metrics/test_view_instrument_match.py -v
  Result: 27 passed, 8 subtests passed (100% green).
• Formatted with black (zero formatting errors).
• All commits include Signed-off-by: Soumyajit Ghosh <jobsoumyajit6124@gmail.com>.

[opentelemetry-pr-dashboard]

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Closed · refreshed 2026-09-25 15:26 UTC

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[somuai]

/dashboard route:reviewers

[opentelemetry-pr-dashboard]

@somuai, this pull request was routed to reviewers. The handoff remains active across pushes until newer actionable human feedback arrives. Top-level feedback through this request will not return; unresolved review threads remain open.

[herin049]

There appears to be some unrelated formatting changes being applied here.

[somuai]

Thanks for pointing that out @herin049. Reverted the unintentional formatting changes on the constructor signature in commit 7b37ad2. The diff is now strictly limited to the wildcard character check and corresponding unit tests.

/dashboard route:reviewers

[herin049]

Going to close this since it's a duplicate.

[somuai]

Hi @herin049 and @lzchen,

Thank you for reviewing and maintaining the repository. I wanted to share a quick point of clarification regarding the timeline and technical scope of this PR relative to #5674.

PR #5673 was submitted on 2026-09-18 at 15:55:19 UTC, approximately 2.5 hours prior to PR #5674 (submitted at 18:18:06 UTC).

In addition, this PR includes a couple of technical details that may be relevant to the review comments left on #5674:

1. Wildcard validation: This PR checks *?[] (any(c in instrument_name for c in "*?[]")), ensuring both [ and ] are caught. PR fix(sdk): detect character pattern wildcards in View instrument_name (#5664) #5674 currently checks *?[, which does not catch ].
2. Test coverage: This PR contains 8 parameterized subtests covering *, ?, [0-9], [!a-z], [abc], [, ], and valid non-wildcard names, which addresses the additional test cases requested on fix(sdk): detect character pattern wildcards in View instrument_name (#5664) #5674.
3. Changelog: The changelog entry here already includes the opentelemetry-sdk prefix and references the character set wildcards.

If you would like to proceed with this PR, I would be happy to have it reopened. Alternatively, if you prefer to keep #5674 since it has already received initial review, please feel free to use the test cases and bracket check from here in that PR. Whichever approach works best for the maintainers works for me.

Thank you again for your time and guidance!