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Merged
timbms merged 1 commit into from
Apr 5, 2026
Merged

Guard NumberState format fallbacks #1100

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144 changes: 132 additions & 12 deletions OpenHABCore/Sources/OpenHABCore/Model/NumberState.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,12 @@
import Foundation

public struct NumberState: CustomStringConvertible, Equatable {
private enum FormatArgument {
case int
case double
case string
}

public var description: String {
toString(locale: Locale.current)
}
Expand Down Expand Up @@ -49,29 +55,143 @@ public struct NumberState: CustomStringConvertible, Equatable {
if let format, !format.isEmpty {
var actualFormat = format
.replacingOccurrences(of: "%unit%", with: unit ?? "")
// %s in Java is for Strings, but does not work in Swift, see
// https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Strings/Articles/formatSpecifiers.html)
.replacingOccurrences(of: "%s", with: "%@")

// Escape trailing % that isn't already escaped (e.g., "%.0f %" should become "%.0f %%")
// This handles server-side format patterns that forgot to escape the percent sign
if actualFormat.hasSuffix(" %"), !actualFormat.hasSuffix(" %%") {
actualFormat = String(actualFormat.dropLast()) + "%%"
}

let formatValue: any CVarArg = if format.contains("%d") {
intValue
} else if format.contains("%s") {
stringValue
} else {
value
guard let normalized = normalizedFormat(actualFormat) else {
return fallbackString
}

switch normalized.argument {
case .int:
return String(format: normalized.format, locale: locale, intValue)
case .double:
return String(format: normalized.format, locale: locale, value)
case .string:
return String(format: normalized.format, locale: locale, stringValue)
}
return String(format: actualFormat, locale: locale, formatValue)
}
return fallbackString
}

private var fallbackString: String {
if let unit, !unit.isEmpty {
return "\(stringValue) \(unit)"
} else {
return stringValue
}
return stringValue
}

private func normalizedFormat(_ format: String) -> (format: String, argument: FormatArgument)? {
var normalized = ""
var index = format.startIndex
var firstArgument: FormatArgument?
var consumesArgumentCount = 0
var usesExplicitArgumentIndex = false

while index < format.endIndex {
let character = format[index]
if character != "%" {
normalized.append(character)
index = format.index(after: index)
continue
}

let percentIndex = index
index = format.index(after: index)

if index == format.endIndex {
return nil
}

if format[index] == "%" {
normalized.append("%%")
index = format.index(after: index)
continue
}

let placeholderStart = index

while index < format.endIndex, "-+# 0".contains(format[index]) {
index = format.index(after: index)
}

while index < format.endIndex, format[index].isNumber {
index = format.index(after: index)
}

if index < format.endIndex, format[index] == "$" {
let digits = format[placeholderStart ..< index]
guard digits == "1" else { return nil }
usesExplicitArgumentIndex = true
index = format.index(after: index)
}

while index < format.endIndex, "-+# 0".contains(format[index]) {
index = format.index(after: index)
}

while index < format.endIndex, format[index].isNumber {
index = format.index(after: index)
}

if index < format.endIndex, format[index] == "." {
index = format.index(after: index)
guard index < format.endIndex else { return nil }
while index < format.endIndex, format[index].isNumber {
index = format.index(after: index)
}
}

if index < format.endIndex, "hlLqjzt".contains(format[index]) {
index = format.index(after: index)
if index < format.endIndex,
((format[format.index(before: index)] == "h" && format[index] == "h") ||
(format[format.index(before: index)] == "l" && format[index] == "l")) {
index = format.index(after: index)
}
}

guard index < format.endIndex else { return nil }

let specifier = format[index]
let argument: FormatArgument
let finalSpecifier: Character
switch specifier {
case "@", "s":
argument = .string
finalSpecifier = "@"
case "d", "i", "u", "o", "x", "X":
argument = .int
finalSpecifier = specifier
case "f", "F", "e", "E", "g", "G", "a", "A":
argument = .double
finalSpecifier = specifier
default:
return nil
}

if let firstArgument, firstArgument != argument {
return nil
}
firstArgument = argument
consumesArgumentCount += 1

normalized.append(contentsOf: format[percentIndex ..< index])
normalized.append(finalSpecifier)
index = format.index(after: index)
}

guard let firstArgument else {
return nil
}
guard consumesArgumentCount == 1 || usesExplicitArgumentIndex else {
return nil
}

return (normalized, firstArgument)
}
}
7 changes: 5 additions & 2 deletions OpenHABCore/Tests/OpenHABCoreTests/NumberStateTests.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -27,8 +27,11 @@ struct NumberStateTests {
#expect(NumberState(value: 100.4, unit: "°C", format: nil).toString(locale: Locale(identifier: "US")) == "100.4 °C")
#expect(NumberState(value: 100.4, unit: nil, format: nil).toString(locale: Locale(identifier: "US")) == "100.4")
#expect(NumberState(value: 100.4, unit: "°C", format: "%.1f %unit%").toString(locale: Locale(identifier: "de")) == "100,4 °C")
// %,.1f is an invalid format string in Swift
#expect(NumberState(value: 100.4, unit: "°C", format: "%,.1f %unit%").toString(locale: Locale(identifier: "de")) == ",.1f °C")
#expect(NumberState(value: 100.4, format: "%1$.1f").toString(locale: Locale(identifier: "US")) == "100.4")
#expect(NumberState(value: 100.4, format: "%1$s").toString(locale: Locale(identifier: "US")) == "100.4")
#expect(NumberState(value: 100.4, unit: "°C", format: "%,.1f %unit%").toString(locale: Locale(identifier: "de")) == "100.4 °C")
#expect(NumberState(value: 100.4, unit: "°C", format: "%1$.1f %2$s").toString(locale: Locale(identifier: "de")) == "100.4 °C")
#expect(NumberState(value: 100.4, unit: "°C", format: "%.1f / %.1f %unit%").toString(locale: Locale(identifier: "de")) == "100.4 °C")
}

@Test("commandString preserves full precision regardless of display format")
Expand Down
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