Use initializer rather than mutating context dictionaries after creation

Author: grynspan

Sources/Testing/ExitTests/ExitTest.swift

@@ -291,9 +291,10 @@ func callExitTest(
   let actualExitCondition = result.exitCondition
 
   // Plumb the exit test's result through the general expectation machinery.
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
-  expectationContext.runtimeValues[.root] = { Expression.Value(reflecting: actualExitCondition) }
+  let expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+    runtimeValues: [.root: { Expression.Value(reflecting: actualExitCondition) }]
+  )
   return check(
     expectedExitCondition == actualExitCondition,
     expectationContext: expectationContext,

Sources/Testing/Expectations/ExpectationChecking+Macro.swift

@@ -236,8 +236,9 @@ public func __checkEscapedCondition(
   isRequired: Bool,
   sourceLocation: SourceLocation
 ) -> Result<Void, any Error> {
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
+  let expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+  )
 
   return check(
     condition,
@@ -265,8 +266,9 @@ public func __checkEscapedCondition<T>(
   isRequired: Bool,
   sourceLocation: SourceLocation
 ) -> Result<T, any Error> where T: ~Copyable {
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
+  let expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+  )
 
   let result = check(
     optionalValue != nil,
@@ -394,8 +396,9 @@ public func __checkClosureCall(
     mismatchExplanationValue = "an error was thrown when none was expected: \(_description(of: error))"
   }
 
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
+  let expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+  )
   return check(
     success,
     expectationContext: expectationContext,
@@ -434,8 +437,9 @@ public func __checkClosureCall(
     mismatchExplanationValue = "an error was thrown when none was expected: \(_description(of: error))"
   }
 
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
+  let expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+  )
   return check(
     success,
     expectationContext: expectationContext,
@@ -520,8 +524,9 @@ public func __checkClosureCall<R>(
   isRequired: Bool,
   sourceLocation: SourceLocation
 ) -> Result<(any Error)?, any Error> {
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
+  var expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+  )
 
   var errorMatches = false
   var mismatchExplanationValue: String? = nil
@@ -574,8 +579,9 @@ public func __checkClosureCall<R>(
   isolation: isolated (any Actor)? = #isolation,
   sourceLocation: SourceLocation
 ) async -> Result<(any Error)?, any Error> {
-  var expectationContext = __ExpectationContext()
-  expectationContext.sourceCode[.root] = sourceCode
+  var expectationContext = __ExpectationContext(
+    sourceCode: [.root: sourceCode],
+  )
 
   var errorMatches = false
   var mismatchExplanationValue: String? = nil