aneurinandClaude Sonnet 5
82611a5e96
Broadens the built-in set with the string/presence checks that came up most often when reaching for this package: - Required[T comparable] non-zero value - Prefix / Suffix / Contains strings.HasPrefix/HasSuffix/Contains - Match(*regexp.Regexp) arbitrary pattern All follow the existing shape: a constructor returning func(T) error, a sentinel error matched with errors.Is, table-driven tests and an Example. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
22 lines
479 B
Go
22 lines
479 B
Go
package validate
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var (
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ErrRequired = NewError("is required")
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)
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// Required validates that a value is not the zero value for its type: an
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// empty string, 0, a nil pointer, and so on.
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//
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// It is defined for comparable types only. For slices and maps, use
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// MinSize(1); for "non-whitespace", combine with a trimming step.
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func Required[T comparable]() func(T) error {
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var zero T
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return func(value T) error {
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if value == zero {
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return ErrRequired
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}
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return nil
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}
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}
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