[NFC] Fix typo, make formatting in PubGrub code consistent

Sources/PackageGraph/Resolution/PubGrub/Assignment.swift

@@ -38,7 +38,10 @@ public struct Assignment: Equatable {
 
     /// An assignment made during decision making.
     public static func decision(_ term: Term, decisionLevel: Int) -> Assignment {
-        assert(term.requirement.isExact, "Cannot create a decision assignment with a non-exact version selection: \(term.requirement)")
+        assert(
+            term.requirement.isExact,
+            "Cannot create a decision assignment with a non-exact version selection: \(term.requirement)"
+        )
 
         return self.init(
             term: term,
@@ -68,9 +71,9 @@ extension Assignment: CustomStringConvertible {
     public var description: String {
         switch self.isDecision {
         case true:
-            return "[Decision \(self.decisionLevel): \(self.term)]"
+            "[Decision \(self.decisionLevel): \(self.term)]"
         case false:
-            return "[Derivation: \(self.term) ← \(self.cause?.description ?? "-")]"
+            "[Derivation: \(self.term) ← \(self.cause?.description ?? "-")]"
         }
     }
 }

Sources/PackageGraph/Resolution/PubGrub/DiagnosticReportBuilder.swift

@@ -19,7 +19,11 @@ struct DiagnosticReportBuilder {
     private var lineNumbers: [Incompatibility: Int] = [:]
     private let provider: ContainerProvider
 
-    init(root: DependencyResolutionNode, incompatibilities: [DependencyResolutionNode: [Incompatibility]], provider: ContainerProvider) {
+    init(
+        root: DependencyResolutionNode,
+        incompatibilities: [DependencyResolutionNode: [Incompatibility]],
+        provider: ContainerProvider
+    ) {
         self.rootNode = root
         self.incompatibilities = incompatibilities
         self.provider = provider
@@ -41,20 +45,20 @@ struct DiagnosticReportBuilder {
             try self.visit(rootCause)
         } else {
             assertionFailure("Unimplemented")
-            self.record(
+            try self.record(
                 rootCause,
-                message: try self.description(for: rootCause),
+                message: self.description(for: rootCause),
                 isNumbered: false
             )
         }
 
-        var content: String = ""
+        var content = ""
         let padding = self.lineNumbers.isEmpty ? 0 : "\(Array(self.lineNumbers.values).last!) ".count
 
         for (idx, line) in self.lines.enumerated() {
             content += String(repeating: " ", count: padding)
             if line.number != -1 {
-                content +=  String(repeating: " ", count: padding)
+                content += String(repeating: " ", count: padding)
                 content += " (\(line.number)) "
             }
             content += line.message.prefix(1).capitalized
@@ -86,9 +90,9 @@ struct DiagnosticReportBuilder {
             let otherLine = self.lineNumbers[cause.other]
 
             if let conflictLine, let otherLine {
-                self.record(
+                try self.record(
                     incompatibility,
-                    message: "\(incompatibilityDesc) because \(try self.description(for: cause.conflict)) (\(conflictLine)) and \(try self.description(for: cause.other)) (\(otherLine).",
+                    message: "\(incompatibilityDesc) because \(self.description(for: cause.conflict)) (\(conflictLine)) and \(self.description(for: cause.other)) (\(otherLine).",
                     isNumbered: isNumbered
                 )
             } else if conflictLine != nil || otherLine != nil {
@@ -106,9 +110,9 @@ struct DiagnosticReportBuilder {
                 }
 
                 try self.visit(withoutLine)
-                self.record(
+                try self.record(
                     incompatibility,
-                    message: "\(conjunction)\(incompatibilityDesc) because \(try self.description(for: withLine)) \(line).",
+                    message: "\(conjunction)\(incompatibilityDesc) because \(self.description(for: withLine)) \(line).",
                     isNumbered: isNumbered
                 )
             } else {
@@ -127,9 +131,9 @@ struct DiagnosticReportBuilder {
                 } else {
                     try self.visit(cause.conflict, isConclusion: true)
                     try self.visit(cause.other)
-                    self.record(
+                    try self.record(
                         incompatibility,
-                        message: "\(conjunction)\(incompatibilityDesc) because \(try self.description(for: cause.conflict)) (\(self.lineNumbers[cause.conflict]!)).",
+                        message: "\(conjunction)\(incompatibilityDesc) because \(self.description(for: cause.conflict)) (\(self.lineNumbers[cause.conflict]!)).",
                         isNumbered: isNumbered
                     )
                 }
@@ -139,9 +143,9 @@ struct DiagnosticReportBuilder {
             let ext = cause.conflict.cause.isConflict ? cause.other : cause.conflict
             let derivedLine = self.lineNumbers[derived]
             if let derivedLine {
-                self.record(
+                try self.record(
                     incompatibility,
-                    message: "\(incompatibilityDesc) because \(try self.description(for: ext)) and \(try self.description(for: derived)) (\(derivedLine)).",
+                    message: "\(incompatibilityDesc) because \(self.description(for: ext)) and \(self.description(for: derived)) (\(derivedLine)).",
                     isNumbered: isNumbered
                 )
             } else if self.isCollapsible(derived) {
@@ -150,27 +154,28 @@ struct DiagnosticReportBuilder {
                     return
                 }
 
-                let collapsedDerived = derivedCause.conflict.cause.isConflict ? derivedCause.conflict : derivedCause.other
+                let collapsedDerived = derivedCause.conflict.cause.isConflict ? derivedCause.conflict : derivedCause
+                    .other
                 let collapsedExt = derivedCause.conflict.cause.isConflict ? derivedCause.other : derivedCause.conflict
 
                 try self.visit(collapsedDerived)
-                self.record(
+                try self.record(
                     incompatibility,
-                    message: "\(conjunction)\(incompatibilityDesc) because \(try self.description(for: collapsedExt)) and \(try self.description(for: ext)).",
+                    message: "\(conjunction)\(incompatibilityDesc) because \(self.description(for: collapsedExt)) and \(self.description(for: ext)).",
                     isNumbered: isNumbered
                 )
             } else {
                 try self.visit(derived)
-                self.record(
+                try self.record(
                     incompatibility,
-                    message: "\(conjunction)\(incompatibilityDesc) because \(try self.description(for: ext)).",
+                    message: "\(conjunction)\(incompatibilityDesc) because \(self.description(for: ext)).",
                     isNumbered: isNumbered
                 )
             }
         } else {
-            self.record(
+            try self.record(
                 incompatibility,
-                message: "\(incompatibilityDesc) because \(try self.description(for: cause.conflict)) and \(try self.description(for: cause.other)).",
+                message: "\(incompatibilityDesc) because \(self.description(for: cause.conflict)) and \(self.description(for: cause.other)).",
                 isNumbered: isNumbered
             )
         }
@@ -213,13 +218,16 @@ struct DiagnosticReportBuilder {
             return "package '\(versionedDependency.identity)' is required using a stable-version but '\(versionedDependency.identity)' depends on an unstable-version package '\(unversionedDependency.identity)'"
         case .incompatibleToolsVersion(let version):
             let term = incompatibility.terms.first!
-            return "\(try self.description(for: term, normalizeRange: true)) contains incompatible tools version (\(version))"
+            return try "\(self.description(for: term, normalizeRange: true)) contains incompatible tools version (\(version))"
         }
 
         let terms = incompatibility.terms
         if terms.count == 1 {
             let term = terms.first!
-            let prefix = try hasEffectivelyAnyRequirement(term) ? term.node.nameForDiagnostics : self.description(for: term, normalizeRange: true)
+            let prefix = try hasEffectivelyAnyRequirement(term) ? term.node.nameForDiagnostics : self.description(
+                for: term,
+                normalizeRange: true
+            )
             return "\(prefix) " + (term.isPositive ? "cannot be used" : "is required")
         } else if terms.count == 2 {
             let term1 = terms.first!
@@ -233,12 +241,12 @@ struct DiagnosticReportBuilder {
             }
         }
 
-        let positive = try terms.filter(\.isPositive).map { try description(for: $0) }
-        let negative = try terms.filter { !$0.isPositive }.map { try description(for: $0) }
+        let positive = try terms.filter(\.isPositive).map { try self.description(for: $0) }
+        let negative = try terms.filter { !$0.isPositive }.map { try self.description(for: $0) }
         if !positive.isEmpty, !negative.isEmpty {
             if positive.count == 1 {
                 let positiveTerm = terms.first { $0.isPositive }!
-                return "\(try self.description(for: positiveTerm, normalizeRange: true)) practically depends on \(negative.joined(separator: " or "))"
+                return try "\(self.description(for: positiveTerm, normalizeRange: true)) practically depends on \(negative.joined(separator: " or "))"
             } else {
                 return "if \(positive.joined(separator: " and ")) then \(negative.joined(separator: " or "))"
             }
@@ -351,8 +359,8 @@ struct DiagnosticReportBuilder {
     }
 }
 
-private extension DependencyResolutionNode {
-    var nameForDiagnostics: String {
+extension DependencyResolutionNode {
+    fileprivate var nameForDiagnostics: String {
         "'\(self.package.identity)'"
     }
 }

Sources/PackageGraph/Resolution/PubGrub/Incompatibility.swift

@@ -63,7 +63,7 @@ extension Incompatibility: CustomStringConvertible {
     }
 }
 
-public extension Incompatibility {
+extension Incompatibility {
     /// Every incompatibility has a cause to explain its presence in the
     /// derivation graph. Only the root incompatibility uses `.root`. All other
     /// incompatibilities are either obtained from dependency constraints,
@@ -89,7 +89,7 @@ public extension Incompatibility {
     ///         │{root 1.0.0}│
     ///         └────────────┘
     /// ```
-    indirect enum Cause: Equatable, Hashable {
+    public indirect enum Cause: Equatable, Hashable {
         public struct ConflictCause: Hashable {
             public let conflict: Incompatibility
             public let other: Incompatibility
@@ -110,7 +110,10 @@ public extension Incompatibility {
         case noAvailableVersion
 
         /// A version-based dependency contains unversioned-based dependency.
-        case versionBasedDependencyContainsUnversionedDependency(versionedDependency: PackageReference, unversionedDependency: PackageReference)
+        case versionBasedDependencyContainsUnversionedDependency(
+            versionedDependency: PackageReference,
+            unversionedDependency: PackageReference
+        )
 
         /// The package's tools version is incompatible.
         case incompatibleToolsVersion(ToolsVersion)

Sources/PackageGraph/Resolution/PubGrub/PartialSolution.swift

@@ -16,7 +16,7 @@ import OrderedCollections
 import struct TSCUtility.Version
 
 /// The partial solution is a constantly updated solution used throughout the
-/// dependency resolution process, tracking know assignments.
+/// dependency resolution process, tracking known assignments.
 public struct PartialSolution {
     var root: DependencyResolutionNode?
 
@@ -37,37 +37,37 @@ public struct PartialSolution {
 
     /// The current decision level.
     public var decisionLevel: Int {
-        decisions.count - 1
+        self.decisions.count - 1
     }
 
     public init(assignments: [Assignment] = []) {
         self.assignments = assignments
         for assignment in assignments {
-            register(assignment)
+            self.register(assignment)
         }
     }
 
     /// A list of all packages that have been assigned, but are not yet satisfied.
     public var undecided: [Term] {
-        _positive.values.filter { !decisions.keys.contains($0.node) }
+        self._positive.values.filter { !self.decisions.keys.contains($0.node) }
     }
 
     /// Create a new derivation assignment and add it to the partial solution's
     /// list of known assignments.
     public mutating func derive(_ term: Term, cause: Incompatibility) {
         let derivation = Assignment.derivation(term, cause: cause, decisionLevel: self.decisionLevel)
         self.assignments.append(derivation)
-        register(derivation)
+        self.register(derivation)
     }
 
     /// Create a new decision assignment and add it to the partial solution's
     /// list of known assignments.
     public mutating func decide(_ node: DependencyResolutionNode, at version: Version) {
-        decisions[node] = version
+        self.decisions[node] = version
         let term = Term(node, .exact(version))
-        let decision = Assignment.decision(term, decisionLevel: decisionLevel)
+        let decision = Assignment.decision(term, decisionLevel: self.decisionLevel)
         self.assignments.append(decision)
-        register(decision)
+        self.register(decision)
     }
 
     /// Populates the _positive and _negative properties with the assignment.
@@ -76,17 +76,17 @@ public struct PartialSolution {
         let pkg = term.node
 
         if let positive = _positive[pkg] {
-            _positive[term.node] = positive.intersect(with: term)
+            self._positive[term.node] = positive.intersect(with: term)
             return
         }
 
-        let newTerm = _negative[pkg].flatMap { term.intersect(with: $0) } ?? term
+        let newTerm = self._negative[pkg].flatMap { term.intersect(with: $0) } ?? term
 
         if newTerm.isPositive {
-            _negative[pkg] = nil
-            _positive[pkg] = newTerm
+            self._negative[pkg] = nil
+            self._positive[pkg] = newTerm
         } else {
-            _negative[pkg] = newTerm
+            self._negative[pkg] = newTerm
         }
     }
 
@@ -95,7 +95,7 @@ public struct PartialSolution {
     public func satisfier(for term: Term) throws -> Assignment {
         var assignedTerm: Term?
 
-        for assignment in assignments {
+        for assignment in self.assignments {
             guard assignment.term.node == term.node else {
                 continue
             }
@@ -114,24 +114,24 @@ public struct PartialSolution {
     public mutating func backtrack(toDecisionLevel decisionLevel: Int) {
         var toBeRemoved: [(Int, Assignment)] = []
 
-        for (idx, assignment) in zip(0..., assignments) {
+        for (idx, assignment) in zip(0..., self.assignments) {
             if assignment.decisionLevel > decisionLevel {
                 toBeRemoved.append((idx, assignment))
             }
         }
 
         for (idx, remove) in toBeRemoved.reversed() {
-            let assignment = assignments.remove(at: idx)
+            let assignment = self.assignments.remove(at: idx)
             if assignment.isDecision {
-                decisions.removeValue(forKey: remove.term.node)
+                self.decisions.removeValue(forKey: remove.term.node)
             }
         }
 
         // FIXME: We can optimize this by recomputing only the removed things.
-        _negative.removeAll()
-        _positive.removeAll()
-        for assignment in assignments {
-            register(assignment)
+        self._negative.removeAll()
+        self._positive.removeAll()
+        for assignment in self.assignments {
+            self.register(assignment)
         }
     }