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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Waiting on reviewers · refreshed 2026-09-21 20:34 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