fix(launcher): harden installer transactions

tests/AcDream.Launcher.Core.Tests/Installation/BakeProgressProtocolTests.cs

@@ -0,0 +1,109 @@
+using AcDream.Launcher.Core.Installation;
+
+namespace AcDream.Launcher.Core.Tests.Installation;
+
+public sealed class BakeProgressProtocolTests
+{
+    [Fact]
+    public void OneStartedProgressAndCompletedSequenceIsAccepted()
+    {
+        var protocol = new BakeProgressProtocol();
+
+        Assert.True(protocol.Observe(new BakeHumanOutputEvent("human")));
+        Assert.True(protocol.Observe(new UnknownBakeProgressEvent(
+            1,
+            "newMetric",
+            "{}")));
+        Assert.True(protocol.Observe(new FutureBakeProgressEvent(
+            2,
+            "started",
+            "{}")));
+        Assert.True(protocol.Observe(new BakeStartedEvent(1, 4, "pak")));
+        Assert.True(protocol.Observe(new BakeWorkProgressEvent(
+            1,
+            "mesh",
+            1,
+            2,
+            0,
+            1,
+            1)));
+        Assert.True(protocol.Observe(new BakeCompletedEvent(1, 4, 100, 0)));
+
+        protocol.CompleteInput();
+
+        Assert.Null(protocol.Violation);
+        Assert.NotNull(protocol.Started);
+        Assert.NotNull(protocol.Completed);
+        Assert.Null(protocol.Error);
+    }
+
+    [Theory]
+    [MemberData(nameof(InvalidKnownSequences))]
+    public void OutOfOrderDuplicateAndPostTerminalKnownEventsAreRejected(
+        BakeProgressEvent[] events)
+    {
+        var protocol = new BakeProgressProtocol();
+
+        foreach (BakeProgressEvent progressEvent in events)
+        {
+            protocol.Observe(progressEvent);
+        }
+
+        protocol.CompleteInput();
+
+        Assert.NotNull(protocol.Violation);
+    }
+
+    [Fact]
+    public void ErrorTerminalCannotBeOverwrittenByContradictoryCompletion()
+    {
+        var protocol = new BakeProgressProtocol();
+        var failure = new BakeErrorEvent(1, "first failure");
+
+        Assert.True(protocol.Observe(new BakeStartedEvent(1, 4, null)));
+        Assert.True(protocol.Observe(failure));
+        Assert.False(protocol.Observe(new BakeCompletedEvent(1, 4, 10, 0)));
+        protocol.CompleteInput();
+
+        Assert.Same(failure, protocol.Error);
+        Assert.Null(protocol.Completed);
+        Assert.Contains("after", protocol.Violation, StringComparison.OrdinalIgnoreCase);
+    }
+
+    public static TheoryData<BakeProgressEvent[]> InvalidKnownSequences => new()
+    {
+        new BakeProgressEvent[]
+        {
+            new BakeWorkProgressEvent(1, "mesh", 0, 1, 0, 0, 0),
+        },
+        new BakeProgressEvent[]
+        {
+            new BakeCompletedEvent(1, 4, 10, 0),
+        },
+        new BakeProgressEvent[]
+        {
+            new BakeErrorEvent(1, "before start"),
+        },
+        new BakeProgressEvent[]
+        {
+            new BakeStartedEvent(1, 4, null),
+            new BakeStartedEvent(1, 4, null),
+        },
+        new BakeProgressEvent[]
+        {
+            new BakeStartedEvent(1, 4, null),
+            new BakeCompletedEvent(1, 4, 10, 0),
+            new BakeCompletedEvent(1, 4, 10, 0),
+        },
+        new BakeProgressEvent[]
+        {
+            new BakeStartedEvent(1, 4, null),
+            new BakeCompletedEvent(1, 4, 10, 0),
+            new BakeWorkProgressEvent(1, "mesh", 1, 1, 0, 1, 0),
+        },
+        new BakeProgressEvent[]
+        {
+            new BakeStartedEvent(1, 4, null),
+        },
+    };
+}