[Copilot]

Integer ValidateRange bounds can allow fractional values outside the declared range on double, single, and decimal parameters.

• Analyzer rule: Add an always-enabled warning for integral bounds on these parameter types.
• Coverage and docs: Add focused tests and document the rule.

# Warning: integer bounds can allow fractional values outside the range
param([double][ValidateRange(0, 100)]$Value)

# Use floating-point bounds
param([double][ValidateRange(0.0, 100.0)]$Value)

• Fixes ValidateRange boundary type vs parameter type check #2199

[Copilot]

🟡 Changes recommended

The rule misses affected array parameters and integral-cast bounds while incorrectly warning on mixed integer/floating-point bounds.

3 open issues

• Handle array element types in ValidateRange checks · New
• Avoid false positives for mixed numeric ValidateRange bounds · New
• Classify ValidateRange casts by resolved target type · New

What changed in this PR

Adds a built-in PSScriptAnalyzer warning for integer ValidateRange bounds on floating-point and decimal parameters, addressing the boundary-validation concern in #2199.

Changes:

• Introduces the always-enabled PSAvoidValidateRangeTypeMismatch warning and diagnostic messages.
• Adds tests for supported parameter types, boundary literals, and qualified attribute names.
• Documents the rule with examples and adds it to the rule index.

File	Description
Tests/​Rules/​AvoidValidateRangeTypeMismatch.tests.ps1	Adds warning and no-warning test cases.
Rules/​Strings.resx	Adds rule metadata and diagnostic text.
Rules/​AvoidValidateRangeTypeMismatch.cs	Implements parameter and boundary-type checks.
docs/​Rules/​README.md	Lists the new warning rule.
docs/​Rules/​AvoidValidateRangeTypeMismatch.md	Explains the rule, examples, and suppression options.

_{Review effort: Balanced}

[Copilot]

🟡 Changes recommended

The rule misses static integral constant bounds and incorrectly flags unrelated custom ValidateRange attributes, causing both false negatives and false positives.

1 open issue

• Handle static integral constants in ValidateRange bounds · New

1 previously missed issue

In code that hasn't changed since last review

Match the resolved ValidateRangeAttribute type

Rules/​AvoidValidateRangeTypeMismatch.cs:121

Discarding the namespace also matches unrelated custom attributes. For example, [Contoso.ValidateRange(0, 100)] on a double parameter triggers this warning even when that attribute is not PowerShell's range validator and has different semantics. Compare the resolved attribute type with System.Management.Automation.ValidateRangeAttribute instead; this supports both short and fully qualified built-in names without reporting unrelated attributes.

3 resolved since last review

• Classify ValidateRange casts by resolved target type
• Avoid false positives for mixed numeric ValidateRange bounds
• Handle array element types in ValidateRange checks

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

The rule skips nullable floating-point parameters, leaving fractional values outside integer ValidateRange bounds undetected; nullable types need unwrapping and coverage for double, single, and decimal parameters.

No open issues 🎉

1 previously missed issue

In code that hasn't changed since last review

Handle nullable floating-point parameters in range validation

Rules/​AvoidValidateRangeTypeMismatch.cs:71

Nullable floating-point parameters are skipped here: param([Nullable[double]][ValidateRange(0, 100)]$Value) resolves to Nullable<double>, which is not in this set. A non-null nullable value is boxed as its underlying numeric type, so integer bounds still permit out-of-range fractional values. Unwrap nullable types before this check and add coverage for nullable double, single, and decimal parameters.

1 resolved since last review

• Handle static integral constants in ValidateRange bounds

_{Review effort: Balanced}

[Christoph Bergmeister (bergmeister)]

🔵 Needs a closer look

The rule skips nullable floating-point parameters, leaving fractional values outside integer ValidateRange bounds undetected; nullable types need unwrapping and coverage for double, single, and decimal parameters.

No open issues 🎉

1 previously missed issue
In code that hasn't changed since last review

Handle nullable floating-point parameters in range validation
Rules/​AvoidValidateRangeTypeMismatch.cs:71

Nullable floating-point parameters are skipped here: param([Nullable[double]][ValidateRange(0, 100)]$Value) resolves to Nullable<double>, which is not in this set. A non-null nullable value is boxed as its underlying numeric type, so integer bounds still permit out-of-range fractional values. Unwrap nullable types before this check and add coverage for nullable double, single, and decimal parameters.

1 resolved since last review

• Handle static integral constants in ValidateRange bounds

Review effort: Balanced

Copilot fix

[Copilot]

🔵 Needs a closer look

The rule skips nullable floating-point parameters, leaving fractional values outside integer ValidateRange bounds undetected; nullable types need unwrapping and cover...

Nullable double, single, and decimal parameter types are now unwrapped before checking; regression tests pass. Fixed in 32bcb67.

[Copilot]

🔵 Needs a closer look

Human assessment is needed because parenthesized integer bounds can bypass the rule’s warning, potentially allowing fractional values outside the declared range.

No open issues 🎉

_{Review effort: Balanced}