Class SseStreamAndHttpAssertions

Namespace

SseAssertions.TUnit

Assembly

SseAssertions.TUnit.dll

Fluent TUnit entry points for asserting on Server-Sent Events streams produced by Stream and HttpResponseMessage receivers: first-event, in-order, retry-directive, content-type, and clean-cancellation checks. The frame-narrowing HasSseEvent chain on these same receivers lives in SseStreamHasEventAssertion and SseResponseHasEventAssertion; the shared read and matching helpers (SseAssertions.TUnit.SseStreamReader, SseAssertions.TUnit.SseEventMatcher) keep the diagnostics identical across all three receivers.

[SuppressMessage("Usage", "VSTHRD200:Use \"Async\" suffix for async methods", Justification = "These are [GenerateAssertion] source methods: the method name becomes the fluent chain entry point (Assert.That(response).HasSseEvent(...)), so an Async suffix would corrupt the assertion surface.")]
public static class SseStreamAndHttpAssertions

Inheritance

object

SseStreamAndHttpAssertions

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

Cancellation semantics: if the supplied CancellationToken fires during the body read, the partial buffer is parsed as best-effort SSE and the assertion runs against the partial event list. On chain pass, the assertion passes; on chain fail, the failure message renders the cancellation-cut-the-read variant (CancellationCutRead(int, int, string)).

On HttpResponseMessage, strictContentType defaults to true: a response without Content-Type: text/event-stream fails with the UnexpectedContentType(string?) diagnostic. Pass false for test mocks that serve SSE without the canonical header.

Methods

EndsCleanlyOnCancellation(Stream, CancellationToken)

Asserts the supplied Stream tears down cleanly when its read is cancelled: the read either completes normally or surfaces cooperative cancellation (OperationCanceledException), but not a transport exception (IOException, HttpRequestException). Pass a token that fires mid-stream; the assertion drains and discards content, checking only teardown behaviour.

[GenerateAssertion]
public static Task<AssertionResult> EndsCleanlyOnCancellation(this Stream stream, CancellationToken cancellationToken = default)

Parameters

stream Stream

The SSE stream whose cancellation teardown to verify.

cancellationToken CancellationToken

The token expected to cancel the read mid-stream.

Returns

Task<AssertionResult>

A passing assertion when the read ends cleanly; otherwise a failing assertion naming the transport exception that surfaced.

Exceptions

ArgumentNullException

stream is null.

EndsCleanlyOnCancellation(HttpResponseMessage, bool, CancellationToken)

Asserts the supplied HttpResponseMessage body tears down cleanly when its read is cancelled: the read either completes normally or surfaces cooperative cancellation (OperationCanceledException), but not a transport exception (IOException, HttpRequestException). Pass a token that fires mid-stream; the assertion drains and discards content, checking only teardown behaviour.

[GenerateAssertion]
public static Task<AssertionResult> EndsCleanlyOnCancellation(this HttpResponseMessage response, bool strictContentType = true, CancellationToken cancellationToken = default)

Parameters

response HttpResponseMessage

The HTTP response carrying the SSE body whose cancellation teardown to verify.

strictContentType bool

When true (the default), the assertion fails if Content-Type's media type is not text/event-stream. Set to false for test mocks that serve SSE without the canonical header.

cancellationToken CancellationToken

The token expected to cancel the read mid-stream.

Returns

Task<AssertionResult>

A passing assertion when the read ends cleanly; otherwise a failing assertion naming the transport exception that surfaced, or the unexpected-content-type diagnostic when strictContentType is on and the header is wrong.

Exceptions

ArgumentNullException

response is null.

HasFirstSseEvent(Stream, string, CancellationToken)

Asserts the first SSE frame in stream has event: equal to eventName. Unlabelled frames match HasFirstSseEvent("message") per the WHATWG default-event-name rule. The full stream is read before parsing; cancellationToken bounds the read.

[GenerateAssertion]
public static Task<AssertionResult> HasFirstSseEvent(this Stream stream, string eventName, CancellationToken cancellationToken = default)

Parameters

stream Stream

The SSE stream.

eventName string

The event-type name expected on the first frame.

cancellationToken CancellationToken

Flows to the stream read.

Returns

Task<AssertionResult>

A passing assertion when the first parsed frame matches; otherwise a failing assertion describing the first event observed, "no events", or the cancellation diagnostic if the read was cut before any frame completed.

Exceptions

ArgumentNullException

stream or eventName is null.

HasFirstSseEvent(HttpResponseMessage, string, bool, CancellationToken)

Asserts the first SSE frame in response's body has event: equal to eventName. Unlabelled frames match HasFirstSseEvent("message") per the WHATWG default-event-name rule. Body is read in full before parsing; cancellationToken bounds the read.

[GenerateAssertion]
public static Task<AssertionResult> HasFirstSseEvent(this HttpResponseMessage response, string eventName, bool strictContentType = true, CancellationToken cancellationToken = default)

Parameters

response HttpResponseMessage

The HTTP response carrying the SSE body.

eventName string

The event-type name expected on the first frame.

strictContentType bool

When true (the default), the assertion fails if Content-Type's media type is not text/event-stream. Set to false for test mocks that serve SSE without the canonical header.

cancellationToken CancellationToken

Flows to the response-body read.

Returns

Task<AssertionResult>

A passing assertion when the first parsed frame matches; otherwise a failing assertion describing the first event observed, "no events", the unexpected content-type diagnostic (when strictContentType is on), or the cancellation diagnostic if the read was cut before any frame completed.

Exceptions

ArgumentNullException

response or eventName is null.

HasSseContentType(HttpResponseMessage, bool)

Asserts the supplied HttpResponseMessage's Content-Type header indicates a Server-Sent Events stream. Header-only check; the response body is not read. Use this as a lightweight smoke-test discriminator for SSE endpoints.

[GenerateAssertion]
public static AssertionResult HasSseContentType(this HttpResponseMessage response, bool strict = false)

Parameters

response HttpResponseMessage

The HTTP response whose Content-Type to inspect.

strict bool

When false (the default), passes when the media type is text/event-stream (case-insensitive); trailing parameters like ; charset=utf-8 are ignored. When true, requires the full Content-Type header to be exactly text/event-stream with no parameters.

Returns

AssertionResult

An assertion that passes when the Content-Type matches per strict.

Exceptions

ArgumentNullException

response is null.

HasSseEventsInOrder(Stream, IReadOnlyList<string>, bool, CancellationToken)

Asserts the supplied Stream contains the named SSE events in order. When strictOrdering is false (default), other events may appear between the named ones; when true, the named events must appear contiguously.

[GenerateAssertion]
public static Task<AssertionResult> HasSseEventsInOrder(this Stream stream, IReadOnlyList<string> eventNames, bool strictOrdering = false, CancellationToken cancellationToken = default)

Parameters

stream Stream

The SSE stream.

eventNames IReadOnlyList<string>

The event-type names expected in order. An empty array trivially passes.

strictOrdering bool

Pass true to require the named events to appear contiguously with no other events between them.

cancellationToken CancellationToken

Flows to the stream read.

Returns

Task<AssertionResult>

An assertion that passes when the order constraint is satisfied; otherwise a failing assertion describing the first violation.

Exceptions

ArgumentNullException

stream or eventNames is null.

HasSseEventsInOrder(HttpResponseMessage, IReadOnlyList<string>, bool, bool, CancellationToken)

Asserts the supplied HttpResponseMessage body contains the named SSE events in order. When strictOrdering is false (default), other events may appear between the named ones; when true, the named events must appear contiguously.

[GenerateAssertion]
public static Task<AssertionResult> HasSseEventsInOrder(this HttpResponseMessage response, IReadOnlyList<string> eventNames, bool strictOrdering = false, bool strictContentType = true, CancellationToken cancellationToken = default)

Parameters

response HttpResponseMessage

The HTTP response carrying the SSE body.

eventNames IReadOnlyList<string>

The event-type names expected in order. An empty array trivially passes.

strictOrdering bool

Pass true to require the named events to appear contiguously with no other events between them.

strictContentType bool

When true (the default), the assertion fails if Content-Type's media type is not text/event-stream.

cancellationToken CancellationToken

Flows to the response-body read.

Returns

Task<AssertionResult>

An assertion that passes when the order constraint is satisfied; otherwise a failing assertion describing the violation or the unexpected content-type.

Exceptions

ArgumentNullException

response or eventNames is null.

HasSseRetryDirective(Stream, int?, CancellationToken)

Asserts the supplied Stream contains a retry: directive. When millis is supplied, requires at least one frame whose retry: value equals it; when null, any retry value passes.

[GenerateAssertion]
public static Task<AssertionResult> HasSseRetryDirective(this Stream stream, int? millis = null, CancellationToken cancellationToken = default)

Parameters

stream Stream

The SSE stream.

millis int?

The required retry: value in milliseconds, or null to accept any value.

cancellationToken CancellationToken

Flows to the stream read.

Returns

Task<AssertionResult>

An assertion that passes when a matching retry: directive is found.

Exceptions

ArgumentNullException

stream is null.

HasSseRetryDirective(HttpResponseMessage, int?, bool, CancellationToken)

Asserts the supplied HttpResponseMessage body contains a retry: directive. When millis is supplied, requires at least one frame whose retry: value equals it; when null, any retry value passes.

[GenerateAssertion]
public static Task<AssertionResult> HasSseRetryDirective(this HttpResponseMessage response, int? millis = null, bool strictContentType = true, CancellationToken cancellationToken = default)

Parameters

response HttpResponseMessage

The HTTP response carrying the SSE body.

millis int?

The required retry: value in milliseconds, or null to accept any value.

strictContentType bool

When true (the default), the assertion fails if Content-Type's media type is not text/event-stream.

cancellationToken CancellationToken

Flows to the response-body read.

Returns

Task<AssertionResult>

An assertion that passes when a matching retry: directive is found, or fails with the unexpected-content-type diagnostic when strictContentType is on and the header is wrong.

Exceptions

ArgumentNullException

response is null.

HasSseRetryDirectiveFirst(Stream, int, CancellationToken)

Asserts the supplied Stream sends a retry: directive before any data-bearing event and that the leading directive's value equals millis: position and value pinned in a single read.

[GenerateAssertion]
public static Task<AssertionResult> HasSseRetryDirectiveFirst(this Stream stream, int millis, CancellationToken cancellationToken = default)

Parameters

stream Stream

The SSE stream.

millis int

The required retry: value, in milliseconds, of the leading directive.

cancellationToken CancellationToken

Flows to the stream read.

Returns

Task<AssertionResult>

An assertion that passes when a retry: millis directive precedes the first data event.

Exceptions

ArgumentNullException

stream is null.

HasSseRetryDirectiveFirst(Stream, CancellationToken)

Asserts the supplied Stream sends a retry: directive before any data-bearing event: the server set the reconnection time before streaming any payload.

[GenerateAssertion]
public static Task<AssertionResult> HasSseRetryDirectiveFirst(this Stream stream, CancellationToken cancellationToken = default)

Parameters

stream Stream

The SSE stream.

cancellationToken CancellationToken

Flows to the stream read.

Returns

Task<AssertionResult>

An assertion that passes when a retry: directive precedes the first data event.

Exceptions

ArgumentNullException

stream is null.

HasSseRetryDirectiveFirst(HttpResponseMessage, bool, CancellationToken)

Asserts the supplied HttpResponseMessage body sends a retry: directive before any data-bearing event.

[GenerateAssertion]
public static Task<AssertionResult> HasSseRetryDirectiveFirst(this HttpResponseMessage response, bool strictContentType = true, CancellationToken cancellationToken = default)

Parameters

response HttpResponseMessage

The HTTP response carrying the SSE body.

strictContentType bool

When true (the default), the assertion fails if Content-Type's media type is not text/event-stream.

cancellationToken CancellationToken

Flows to the response-body read.

Returns

Task<AssertionResult>

An assertion that passes when a retry: directive precedes the first data event, or fails with the unexpected-content-type diagnostic when strictContentType is on and the header is wrong.

Exceptions

ArgumentNullException

response is null.

HasSseRetryDirectiveFirst(HttpResponseMessage, int, bool, CancellationToken)

Asserts the supplied HttpResponseMessage body sends a retry: directive before any data-bearing event and that the leading directive's value equals millis: position and value pinned in a single read of the forward-only response body, which a separate position assertion and value assertion cannot both inspect.

[GenerateAssertion]
public static Task<AssertionResult> HasSseRetryDirectiveFirst(this HttpResponseMessage response, int millis, bool strictContentType = true, CancellationToken cancellationToken = default)

Parameters

response HttpResponseMessage

The HTTP response carrying the SSE body.

millis int

The required retry: value, in milliseconds, of the leading directive.

strictContentType bool

When true (the default), the assertion fails if Content-Type's media type is not text/event-stream.

cancellationToken CancellationToken

Flows to the response-body read.

Returns

Task<AssertionResult>

An assertion that passes when a retry: millis directive precedes the first data event, or fails with the unexpected-content-type diagnostic when strictContentType is on and the header is wrong.

Exceptions

ArgumentNullException

response is null.