Fix warn messages in doc (#1255)

* Fix warn messages in doc

* use -Wconf to silence warnings about non-exhaustive pattern matching in documentation

* add Xfatal-warnings to docs project

build.sbt

@@ -283,6 +283,8 @@ lazy val docs = project
     skip in publish := true,
     moduleName := "scalafix-docs",
     scalaVersion := scala213,
+    scalacOptions += "-Wconf:msg='match may not be exhaustive':s", // silence exhaustive pattern matching warning for documentation
+    scalacOptions += "-Xfatal-warnings",
     mdoc := run.in(Compile).evaluated,
     crossScalaVersions := List(scala213),
     libraryDependencies ++= List(

docs/developers/semantic-tree.md

@@ -32,7 +32,6 @@ The variable `doc` in the code examples is an implicit instance of
 ```scala mdoc:passthrough
 import scalafix.docs.PatchDocs
 def println(a: Any): Unit = PatchDocs.println(a)
-import scalafix.docs.PatchDocs._
 implicit var doc: SemanticDocument = null
 ```
 
@@ -53,21 +52,21 @@ parameters
 doc.tree.traverse {
   // Option.apply
   case option @ Term.Select(Term.Name("Option"), Term.Name("apply")) =>
-    println("synthetic = " + option.synthetic)
-    println("structure = " + option.synthetic.structure)
+    println("synthetic = " + option.synthetics)
+    println("structure = " + option.synthetics.structure)
 }
 ```
 
 The asterisk `*` represents an `OriginalTree` node that matches the enclosing
 non-synthetic tree, which is `List` in this example.
 
-The `.synthetic` method is only available on `Term` nodes, using the method on
+The `.synthetics` method is only available on `Term` nodes, using the method on
 other tree nodes such as types results in compilation error
 
 ```scala mdoc:fail
 doc.tree.traverse {
   case app @ Type.Name("App") =>
-    println(".synthetic = " + app.synthetic)
+    println(".synthetic = " + app.synthetics)
 }
 ```
 
@@ -83,21 +82,21 @@ Option[Int](2) // inferred: Option.apply[Int](2)
 """)
 ```
 
-Use `Tree.synthetic` in combination with `SemanticTree.symbol` to get the symbol
+Use `Tree.synthetics` in combination with `SemanticTree.symbol` to get the symbol
 of those inferred `.apply` method calls.
 
 ```scala mdoc
 doc.tree.traverse {
   case Term.Apply(add @ q"add", List(q"2")) =>
     println("add(2)")
-    println("synthetic = " + add.synthetic)
-    println("symbol    = " + add.synthetic.flatMap(_.symbol).structure)
-    println("structure = " + add.synthetic.structure)
+    println("synthetic = " + add.synthetics)
+    println("symbol    = " + add.synthetics.flatMap(_.symbol).structure)
+    println("structure = " + add.synthetics.structure)
   case Term.ApplyType(option @ q"Option", List(t"Int")) =>
     println("Option[Int]")
-    println("synthetic = " + option.synthetic)
-    println("symbol    = " + option.synthetic.flatMap(_.symbol).structure)
-    println("structure = " + option.synthetic.structure)
+    println("synthetic = " + option.synthetics)
+    println("symbol    = " + option.synthetics.flatMap(_.symbol).structure)
+    println("structure = " + option.synthetics.structure)
 }
 ```
 
@@ -124,14 +123,14 @@ Main.run             // implicit argument: message
 """)
 ```
 
-Use `Tree.synthetic` to look up an implicit argument for any `Term` node.
+Use `Tree.synthetics` to look up an implicit argument for any `Term` node.
 
 ```scala mdoc
 doc.tree.traverse {
-  case term: Term if term.synthetic.isDefined =>
+  case term: Term if term.synthetics.nonEmpty =>
     println("term      = " + term.syntax)
-    println("synthetic = " + term.synthetic)
-    println("structure = " + term.synthetic.structure)
+    println("synthetics = " + term.synthetics)
+    println("structure = " + term.synthetics.structure)
 }
 ```
 
@@ -146,18 +145,18 @@ List(1) ++ List(2)
 """)
 ```
 
-Use the `Term.ApplyInfix.syntheticOperator` to look up inferred type parameters
+Use the `Term.ApplyInfix.syntheticOperators` to look up inferred type parameters
 of infix operators.
 
 ```scala mdoc
 doc.tree.traverse {
   case concat @ Term.ApplyInfix(_, Term.Name("++"), _, _) =>
-    println(".syntheticOperator = " + concat.syntheticOperator)
-    println(".structure         = " + concat.syntheticOperator.structure)
+    println(".syntheticOperators = " + concat.syntheticOperators)
+    println(".structure         = " + concat.syntheticOperators.structure)
 }
 ```
 
-The `.syntheticOperator` method is only available for `Term.ApplyInfix` nodes,
+The `.syntheticOperators` method is only available for `Term.ApplyInfix` nodes,
 using the method on other node types results in a compilation error
 
 [comment]: <> (Todo: add mdoc:fail for this snippet!) 
@@ -173,7 +172,7 @@ Beware that looking up synthetics for the infix operator name returns nothing
 ```scala mdoc
 doc.tree.traverse {
   case concat @ Term.Name("++") =>
-    println(".synthetic = " + concat.synthetic)
+    println(".synthetics = " + concat.synthetics)
 }
 ```
 
@@ -191,18 +190,18 @@ for (number <- numbers) println(number)
 """)
 ```
 
-Use `Tree.synthetic` on the tree node `Term.ForYield` to inspect the desugared
+Use `Tree.synthetics` on the tree node `Term.ForYield` to inspect the desugared
 version of the `for { .. } yield` expression
 
 ```scala mdoc
 doc.tree.traverse {
   case forYield: Term.ForYield =>
-    println(".synthetic = " + forYield.synthetic)
+    println(".synthetics = " + forYield.synthetics)
 }
 ```
 
 The `orig(List(1, 2))` and `orig(1.to(i)` parts represent `OriginalSubTree`
-nodes that match non-synthetic tree nodes from the original for-comprension.
+nodes that match non-synthetic tree nodes from the original for-comprehension.
 
 ## Known limitations
 
@@ -228,7 +227,7 @@ Observe the empty `withFilter` body and `<unknown>` parameter symbol.
 ```scala mdoc
 doc.tree.traverse {
   case forYield: Term.ForYield =>
-    println(forYield.synthetic)
+    println(forYield.synthetics)
 }
 ```
 
@@ -250,7 +249,7 @@ Observe the `<unknown>` parameter symbol to the final call to `map`.
 ```scala mdoc
 doc.tree.traverse {
   case forYield: Term.ForYield =>
-    println(forYield.synthetic)
+    println(forYield.synthetics)
 }
 ```
 

docs/developers/symbol-information.md

@@ -238,9 +238,9 @@ Use `ClassSignature.parents` and `TypeRef.symbol` to lookup the class hierarchy.
 def getParentSymbols(symbol: Symbol): Set[Symbol] =
   symbol.info.get.signature match {
     case ClassSignature(_, parents, _, _) =>
-      Set(symbol) ++ parents.flatMap {
+      Set(symbol) ++ parents.collect {
         case TypeRef(_, symbol, _) => getParentSymbols(symbol)
-      }
+      }.flatten
   }
 getParentSymbols(Symbol("java/lang/String#"))
 ```
@@ -256,9 +256,9 @@ def getClassMethods(symbol: Symbol): Set[SymbolInformation] =
   symbol.info.get.signature match {
     case ClassSignature(_, parents, _, declarations) =>
       val methods = declarations.filter(_.isMethod)
-      methods.toSet ++ parents.flatMap {
+      methods.toSet ++ parents.collect {
         case TypeRef(_, symbol, _) => getClassMethods(symbol)
-      }
+      }.flatten
     case _ => Set.empty
   }
 getClassMethods(Symbol("scala/Some#")).take(5)
@@ -368,9 +368,9 @@ def getMethodOverloads(classSymbol: Symbol, methodName: String): Set[SymbolInfor
         declaration.isMethod &&
         declaration.displayName == methodName
       }
-      overloadedMethods.toSet ++ parents.flatMap {
+      overloadedMethods.toSet ++ parents.collect {
         case TypeRef(_, symbol, _) => getMethodOverloads(symbol, methodName)
-      }
+      }.flatten
     case _ => Set.empty
   }
 getMethodOverloads(Symbol("java/lang/String#"), "substring")

docs/developers/symbol-matcher.md

@@ -30,7 +30,6 @@ import scala.meta._
 ```scala mdoc:passthrough
 import scalafix.docs.PatchDocs
 def println(a: Any): Unit = PatchDocs.println(a)
-import scalafix.docs.PatchDocs._
 ```
 
 ## SemanticDB

docs/developers/tutorial.md

@@ -162,7 +162,7 @@ trees.
 
 ```scala mdoc
 println(q"complete(true)".structure)     // line wrap at 80th column
-println(q"complete(true)".structure(30)) // line wrap at 30th column
+println(q"complete(true)".structureWidth(30)) // line wrap at 30th column
 ```
 
 The output of `tree.structure` can be copy-pasted for use in pattern matching.

scalafix-docs/src/main/scala/docs/website.scala

@@ -84,14 +84,16 @@ package object website {
       default: T
   )(implicit settings: Settings[T], ev: T <:< Product): List[(Setting, Any)] = {
     settings.settings
-      .zip(default.productIterator.toIterable)
+      .zip(default.productIterator.iterator.to(Iterable))
       .filterNot { case (setting, _) => setting.isHidden }
       .flatMap {
         case (s, d: SimpleDefinitions) =>
           (s, d.kinds.mkString("['", "', '", "']")) :: Nil
         case (deepSetting, defaultSetting: Product)
             if deepSetting.underlying.nonEmpty =>
-          deepSetting.flat.zip(defaultSetting.productIterator.toIterable)
+          deepSetting.flat.zip(
+            defaultSetting.productIterator.iterator.to(Iterable)
+          )
         case (s, lst: Iterable[_]) =>
           val rendered = lst.map(render)
           val string =

scalafix-docs/src/main/scala/scalafix/docs/PatchDocs.scala

@@ -28,7 +28,7 @@ object PatchDocs {
           doc
             .nested(ctx.indentCount * ctx.indentStep)
             .renderStream(ctx.leftOffset)
-            .toIterator
+            .iterator
         }
       x match {
         case t: SemanticTree =>

scalafix-tests/unit/src/main/scala/scalafix/test/ExplicitSynthetic.scala

@@ -24,10 +24,10 @@ class ExplicitSynthetic(insertInfixTypeParam: Boolean)
       case Term.Select(_, Term.Name("apply")) =>
         // happens for explicit "List.apply" because Synthetic.symbol returns Some(symbol)
         // for OriginalTree.
-        None
+        List()
       case infix: Term.ApplyInfix if insertInfixTypeParam =>
         for {
-          synthetic <- infix.syntheticOperator.collect {
+          synthetic <- infix.syntheticOperators.collect {
             case tappl: TypeApplyTree => tappl
           }
         } yield {
@@ -43,7 +43,7 @@ class ExplicitSynthetic(insertInfixTypeParam: Boolean)
         }
       case t: Term =>
         for {
-          synthetic <- t.synthetic
+          synthetic <- t.synthetics
           sym <- synthetic.symbol
           if sym.displayName == "apply"
         } yield {