Add test expectation

Author: finestructure

Tests/AppTests/AnalyzerTests.swift

@@ -1157,6 +1157,23 @@ extension AllTests.AnalyzerTests {
         }
     }
 
+    @Test func processingEnvironmentVariable() async throws {
+        let environment = QueueIsolated<[String: String]?>(nil)
+        try await withDependencies {
+            $0.fileManager.fileExists = { _ in true }
+            $0.shell.run = { @Sendable _, _, env in
+                environment.setValue(env)
+                return #"{"name":"foo","products":[],"targets":[]}"#
+            }
+        } operation: {
+            _ = try await Analyze.dumpPackage(at: "/somepath")
+            try environment.withValue {
+                let keys = try #require($0?.keys)
+                #expect(keys.contains("SPI_PROCESSING"))
+            }
+        }
+    }
+
     @Test func issue_577() async throws {
         // Duplicate "latest release" versions
         // https://github.com/SwiftPackageIndex/SwiftPackageIndex-Server/issues/577