Type narrowing union types via return type of method call#1497
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soutaro merged 1 commit intosoutaro:masterfrom Feb 28, 2025
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Type narrowing union types via return type of method call#1497soutaro merged 1 commit intosoutaro:masterfrom
soutaro merged 1 commit intosoutaro:masterfrom
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This tries to narrow types unions by the return type of the method call. If the return type of the method is always truthy or falsy, the receiver type will be narrowed on the truthy branch and the falsy branch. This helps to narrow types via method definitions (ex. `#nil?`, `#present?`, `#blank?` and so on).
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This updates the return types of `#present?` and `#blank?` to true, false or bool to narrow the type of receiver. Since 1.10, Steep can narrow the type of receiver via the return type of the method when the type of receiver is union. For example, a receiver typed as will be narrowed to `String` on the `if present?` block, and be narrowed to `String | nil` on the `else` block because `String#present?` returns bool and `NilClass#present?` returns false. refs: * https://github.com/soutaro/steep/wiki/Release-Note-1.10 (unreleased yet) * soutaro/steep#1497
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This updates the return types of `#present?` and `#blank?` to narrow the type of receiver possibly. Since 1.10, Steep can narrow the type of receiver via the return type of the method when the type of receiver is union. For example, a receiver typed as will be narrowed to `String` on the `if present?` block, and be narrowed to `String | nil` on the `else` block because `String#present?` returns bool and `NilClass#present?` returns false. refs: * https://github.com/soutaro/steep/wiki/Release-Note-1.10 (unreleased yet) * soutaro/steep#1497
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This updates the return types of `#present?` and `#blank?` to narrow the type of receiver possibly. Since 1.10, Steep can narrow the type of receiver via the return type of the method when the type of receiver is union. For example, a receiver typed as will be narrowed to `String` on the `if present?` block, and be narrowed to `String | nil` on the `else` block because `String#present?` returns bool and `NilClass#present?` returns false. ```ruby var = ... # String | nil if var.present? # var is narrowed to String else # var is narrowed to String | nil end ``` refs: * https://github.com/soutaro/steep/wiki/Release-Note-1.10 (unreleased yet) * soutaro/steep#1497
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This updates the return types of `#present?` and `#blank?` to narrow the type of receiver possibly. Since 1.10, Steep can narrow the type of receiver via the return type of the method when the type of receiver is union. For example, a receiver typed as will be narrowed to `String` on the `if present?` block, and be narrowed to `String | nil` on the `else` block because `String#present?` returns bool and `NilClass#present?` returns false. ```ruby var = ... # String | nil if var.present? # var is narrowed to String else # var is narrowed to String | nil end ``` refs: * https://github.com/soutaro/steep/wiki/Release-Note-1.10 (unreleased yet) * soutaro/steep#1497
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This tries to narrow types unions by the return type of the method call. If the return type of the method is always truthy or falsy, the receiver type will be narrowed on the truthy branch and the falsy branch.
This helps to narrow types via method definitions (ex.
#nil?,#present?,#blank?and so on).