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glbrnttMordil
glbrntt
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Mordil
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Add SET options
Motivation: SET has a range of options for setting expirations and conditionally setting a value. Modification: - Add another `set` function with a range of options. Options are modelled as `struct`s backed by private `enum`s to allow additional options to be added without breaking API. - Added tests Result: Options may be specified with `set`, and resolves #67
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‎Sources/RediStack/Commands/StringCommands.swift‎

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@@ -93,6 +93,106 @@ extension RedisClient {
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// MARK: Set
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/// A condition which must hold true in order for a key to be set.
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///
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/// See [https://redis.io/commands/set](https://redis.io/commands/set)
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public struct RedisSetCommandCondition: Hashable {
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private enum Condition: String, Hashable {
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case keyExists = "XX"
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case keyDoesNotExist = "NX"
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}
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private let condition: Condition?
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private init(_ condition: Condition?) {
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self.condition = condition
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}
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/// The `RESPValue` representation of the condition.
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@usableFromInline
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internal var commandArgument: RESPValue? {
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return self.condition.map { RESPValue(from: $0.rawValue) }
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}
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}
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extension RedisSetCommandCondition {
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/// No condition is required to be met in order to set the key's value.
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public static let none = RedisSetCommandCondition(.none)
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/// Only set the key if it already exists.
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///
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/// Redis documentation refers to this as the option "XX".
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public static let keyExists = RedisSetCommandCondition(.keyExists)
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/// Only set the key if it does not already exist.
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///
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/// Redis documentation refers to this as the option "NX".
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public static let keyDoesNotExist = RedisSetCommandCondition(.keyDoesNotExist)
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}
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/// The expiration to apply when setting a key.
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///
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/// See [https://redis.io/commands/set](https://redis.io/commands/set)
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public struct RedisSetCommandExpiration: Hashable {
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private enum Expiration: Hashable {
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case keepExisting
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case seconds(Int)
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case milliseconds(Int)
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}
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private let expiration: Expiration
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private init(_ expiration: Expiration) {
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self.expiration = expiration
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}
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/// An array of `RESPValue`s representing this expiration.
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@usableFromInline
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internal func asCommandArguments() -> [RESPValue] {
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switch self.expiration {
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case .keepExisting:
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return [RESPValue(from: "KEEPTTL")]
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case .seconds(let amount):
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return [RESPValue(from: "EX"), amount.convertedToRESPValue()]
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case .milliseconds(let amount):
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return [RESPValue(from: "PX"), amount.convertedToRESPValue()]
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}
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}
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}
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extension RedisSetCommandExpiration {
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/// Retain the existing expiration associated with the key, if one exists.
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///
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/// Redis documentation refers to this as "KEEPTTL".
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/// - Important: This is option is only available in Redis 6.0+. An error will be returned if this value is sent in lower versions of Redis.
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public static let keepExisting = RedisSetCommandExpiration(.keepExisting)
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/// Expire the key after the given number of seconds.
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///
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/// Redis documentation refers to this as the option "EX".
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/// - Important: The actual amount used will be the specified value or `1`, whichever is larger.
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public static func seconds(_ amount: Int) -> RedisSetCommandExpiration {
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return RedisSetCommandExpiration(.seconds(max(amount, 1)))
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}
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/// Expire the key after the given number of milliseconds.
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///
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/// Redis documentation refers to this as the option "PX".
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/// - Important: The actual amount used will be the specified value or `1`, whichever is larger.
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public static func milliseconds(_ amount: Int) -> RedisSetCommandExpiration {
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return RedisSetCommandExpiration(.milliseconds(max(amount, 1)))
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}
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}
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/// The result of a `SET` command.
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public enum RedisSetCommandResult: Hashable {
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/// The command completed successfully.
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case ok
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/// The command was not performed because a condition was not met.
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///
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/// See `RedisSetCommandCondition`.
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case conditionNotMet
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}
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extension RedisClient {
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/// Append a value to the end of an existing entry.
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/// - Note: If the key does not exist, it is created and set as an empty string, so `APPEND` will be similar to `SET` in this special case.
@@ -133,6 +233,45 @@ extension RedisClient {
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.map { _ in () }
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}
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/// Sets the key to the provided value with options to control how it is set.
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///
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/// [https://redis.io/commands/set](https://redis.io/commands/set)
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/// - Important: Regardless of the type of data stored at the key, it will be overwritten to a "string" data type.
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///
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/// ie. If the key is a reference to a Sorted Set, its value will be overwritten to be a "string" data type.
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///
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/// - Parameters:
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/// - key: The key to use to uniquely identify this value.
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/// - value: The value to set the key to.
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/// - condition: The condition under which the key should be set.
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/// - expiration: The expiration to use when setting the key. No expiration is set if `nil`.
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/// - Returns: A `NIO.EventLoopFuture` indicating the result of the operation;
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/// `.ok` if the operation was successful and `.conditionNotMet` if the specified `condition` was not met.
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///
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/// If the condition `.none` was used, then the result value will always be `.ok`.
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public func set<Value: RESPValueConvertible>(
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_ key: RedisKey,
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to value: Value,
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onCondition condition: RedisSetCommandCondition,
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expiration: RedisSetCommandExpiration? = nil
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) -> EventLoopFuture<RedisSetCommandResult> {
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var args: [RESPValue] = [
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.init(from: key),
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value.convertedToRESPValue()
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]
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if let conditionArgument = condition.commandArgument {
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args.append(conditionArgument)
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}
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if let expiration = expiration {
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args.append(contentsOf: expiration.asCommandArguments())
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}
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return self.send(command: "SET", with: args)
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.map { return $0.isNull ? .conditionNotMet : .ok }
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}
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/// Sets the key to the provided value if the key does not exist.
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///
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/// [https://redis.io/commands/setnx](https://redis.io/commands/setnx)

‎Tests/RediStackIntegrationTests/Commands/StringCommandsTests.swift‎

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@@ -52,6 +52,70 @@ final class StringCommandsTests: RediStackIntegrationTestCase {
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XCTAssertEqual(val, "value")
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}
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func test_set_condition() throws {
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XCTAssertEqual(try connection.set(#function, to: "value", onCondition: .keyExists).wait(), .conditionNotMet)
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XCTAssertEqual(try connection.set(#function, to: "value", onCondition: .keyDoesNotExist).wait(), .ok)
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XCTAssertEqual(try connection.set(#function, to: "value", onCondition: .keyDoesNotExist).wait(), .conditionNotMet)
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XCTAssertEqual(try connection.set(#function, to: "value", onCondition: .keyExists).wait(), .ok)
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XCTAssertEqual(try connection.set(#function, to: "value", onCondition: .none).wait(), .ok)
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}
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func test_set_expiration() throws {
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let expireInSecondsKey = RedisKey("\(#function)-seconds")
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let expireInSecondsResult = connection.set(
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expireInSecondsKey,
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to: "value",
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onCondition: .none,
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expiration: .seconds(42)
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)
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XCTAssertEqual(try expireInSecondsResult.wait(), .ok)
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let ttl = try connection.ttl(expireInSecondsKey).wait()
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switch ttl {
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case .keyDoesNotExist, .unlimited:
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XCTFail("Unexpected TTL for key \(expireInSecondsKey)")
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case .limited(let lifetime):
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XCTAssertGreaterThan(lifetime.timeAmount, .nanoseconds(0))
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XCTAssertLessThanOrEqual(lifetime.timeAmount, .seconds(42))
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}
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let expireInMillisecondsKey = RedisKey("\(#function)-milliseconds")
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let expireInMillisecondsResult = connection.set(
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expireInMillisecondsKey,
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to: "value",
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onCondition: .none,
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expiration: .milliseconds(42_000)
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)
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XCTAssertEqual(try expireInMillisecondsResult.wait(), .ok)
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let pttl = try connection.ttl(expireInMillisecondsKey).wait()
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switch pttl {
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case .keyDoesNotExist, .unlimited:
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XCTFail("Unexpected TTL for key \(expireInMillisecondsKey)")
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case .limited(let lifetime):
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XCTAssertGreaterThan(lifetime.timeAmount, .nanoseconds(0))
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XCTAssertLessThanOrEqual(lifetime.timeAmount, .milliseconds(42_000))
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}
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}
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func test_set_condition_and_expiration() throws {
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let setFailedResult = connection.set(#function, to: "value", onCondition: .keyExists, expiration: .seconds(42))
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XCTAssertEqual(try setFailedResult.wait(), .conditionNotMet)
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let setResult = connection.set(#function, to: "value", onCondition: .keyDoesNotExist, expiration: .seconds(42))
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XCTAssertEqual(try setResult.wait(), .ok)
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let ttl = try connection.ttl(#function).wait()
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switch ttl {
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case .keyDoesNotExist, .unlimited:
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XCTFail("Unexpected TTL for key \(#function)")
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case .limited(let lifetime):
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XCTAssertGreaterThan(lifetime.timeAmount, .nanoseconds(0))
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XCTAssertLessThanOrEqual(lifetime.timeAmount, .seconds(42))
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}
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}
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func test_setnx() throws {
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XCTAssertTrue(try connection.setnx(#function, to: "value").wait())
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XCTAssertFalse(try connection.setnx(#function, to: "value").wait())

‎Tests/RediStackIntegrationTests/XCTestManifests.swift‎

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@@ -157,6 +157,9 @@ extension StringCommandsTests {
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("test_mget", test_mget),
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("test_mset", test_mset),
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("test_msetnx", test_msetnx),
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("test_set_condition_and_expiration", test_set_condition_and_expiration),
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("test_set_condition", test_set_condition),
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("test_set_expiration", test_set_expiration),
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("test_set", test_set),
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("test_setnx", test_setnx),
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]

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