StackExchange.Redis migration code fix

The Respire package includes an opt-in Roslyn analyzer and code fix for the classic StackExchange.Redis IDatabase API. It resolves method symbols from the actual StackExchange.Redis assembly; unrelated methods with matching names are ignored. Tests compile the source and the converted result against StackExchange.Redis 3.4.0 and the real Respire library. The 4.0 command-group API is outside this tool's scope.

Install and enable

Keep your existing StackExchange.Redis reference and add Respire:

dotnet add package Respire

The analyzer is bundled under analyzers/dotnet/cs; there is no separate Respire.Analyzers NuGet package. Do not exclude analyzer assets from the reference. Use a Roslyn code-fix host such as Visual Studio 2022 17.8 or later, with an SDK that supports your application's target framework.

Enable these rules in the project's .editorconfig while migrating:

[*.cs]
dotnet_diagnostic.RESP007.severity = suggestion
dotnet_diagnostic.RESP008.severity = warning

• RESP007 marks the first supported call in a method. Use the lightbulb action Migrate method and IDatabase parameter to RespireClient. It changes the parameter type and every database call in that method together.
• RESP008 marks calls requiring manual migration, including GetDatabase connection setup. It offers no automatic fix.

Both rules are disabled by default. Remove the opt-in after completing migration. Fix All supports document, project, and solution scopes. It validates the combined edits before offering them, including signature collisions between otherwise valid fixes.

Supported boundary and calls

Automatic conversion currently targets static async methods with exactly one IDatabase parameter, used only as the receiver of supported calls. There must be no nested lambdas or local functions, parameter attributes/defaults, preprocessor directives, other database receivers, extension methods, or partial-method declaration. Calls must be immediately awaited; ConfigureAwait(bool) is preserved. The parameter becomes global::Respire.RespireClient, retaining its name and nullable annotation.

StackExchange.Redis expression	Converted Respire expression
(string?)await db.StringGetAsync(key)	await db.Strings.GetStringAsync(key)
(byte[]?)await db.StringGetAsync(key)	await db.Strings.GetBytesAsync(key)
await db.StringSetAsync(key, "value")	await db.Strings.SetAsync(key, "value")
await db.KeyExistsAsync(key)	await db.Keys.ExistsAsync(key)
await db.KeyDeleteAsync(key) when its Boolean result is used	(await db.Keys.DeleteAsync(key, cancellationToken: default) != 0)
await db.KeyDeleteAsync(key); with the result discarded	await db.Keys.DeleteAsync(key, cancellationToken: default);

Keys must be string expressions. SET values must be non-null constant strings, including constant expressions. Named key/value arguments retain their evaluation order. GET requires an explicit string or byte-array cast: missing keys remain null, empty values remain empty, and the byte-array path does not decode binary data as text.

Any explicit optional argument requires manual review, including CommandFlags.None, expiry, When, and keepTtl. So do array overloads, RedisKey/RedisValue arguments, binary keys, nonconstant or nullable SET values, unawaited tasks, RedisValue results, instance methods, database aliases, batches, transactions, and other commands. A null StackExchange.Redis SET value can delete a key; the tool never rewrites it to a native SET that rejects null. It never drops an option to make a call fit.

The fix checks compiler diagnostics in the edited document and its partial-type declarations. It also scans syntax in the project and its transitive dependents, including generated source, for uses of the method's name. Any matching name use requires manual migration, even if it currently refers to a different method or another kind of symbol. This conservative check protects calls and method groups from silently selecting a different overload or becoming ambiguous through using static after the signature changes. Non-C# dependent projects also require manual migration. The fix does not run a full compiler diagnostic pass across dependent projects. It is also withheld if the edited document or its partial-type declarations have compiler errors or a Respire reference is missing; unrelated errors in other documents do not suppress it. RESP007 can therefore appear without an available fix. Address relevant compilation errors and migrate callers/boundaries first, or migrate that method manually. External callers outside the loaded solution cannot be checked: changing a public method's parameter is a public API change that must be coordinated with its consumers.

Example fixture

Before:

using StackExchange.Redis;

public static async Task<string?> ReadAsync(IDatabase database, string key)
{
    return (string?)await database.StringGetAsync(key).ConfigureAwait(false);
}

After applying the fix:

public static async Task<string?> ReadAsync(global::Respire.RespireClient database, string key)
{
    return await database.Strings.GetStringAsync(key).ConfigureAwait(false);
}

The sample fixture contains an existence check, deletion with Boolean handling, a write, a nullable text read, and a binary read. The tests apply Fix All without manual source edits and compile the result against real Respire references. This fixture starts at the application boundary where the host supplies a configured database; it does not create a connection.

Configure the host explicitly

Connection creation, lifetime, dependency injection, endpoint selection and logical database selection remain manual work. A call such as connection.GetDatabase(3) raises RESP008; the tool never replaces it with a client using database zero. Configure the corresponding Respire client with the same database and intended topology before passing it to a migrated method. Review routing, key prefixes, caching, retry policy, value codecs and exception handling as part of that setup. See connections and the API comparison and migration examples.

For code that must retain StackExchange.Redis contracts during a gradual migration, use the incremental migration adapter.