Coverage: escape strings before serializing statements, fix #15384

Author: TheElectronWill

compiler/src/dotty/tools/dotc/coverage/Location.scala

@@ -31,7 +31,7 @@ object Location:
 
     val ownerDenot = ctx.owner.denot
     val enclosingClass = ownerDenot.enclosingClass
-    val packageName = ownerDenot.enclosingPackageClass.name.toSimpleName.toString
+    val packageName = ownerDenot.enclosingPackageClass.fullName.toSimpleName.toString
     val className = enclosingClass.name.toSimpleName.toString
     val methodName = ownerDenot.enclosingMethod.name.toSimpleName.toString
 

compiler/src/dotty/tools/dotc/coverage/Serializer.scala

@@ -4,6 +4,7 @@ package coverage
 import java.nio.file.{Path, Paths, Files}
 import java.io.Writer
 import scala.language.unsafeNulls
+import scala.collection.mutable.StringBuilder
 
 /**
  * Serializes scoverage data.
@@ -62,25 +63,49 @@ object Serializer:
     def writeStatement(stmt: Statement, writer: Writer): Unit =
       // Note: we write 0 for the count because we have not measured the actual coverage at this point
       writer.write(s"""${stmt.id}
-                      |${getRelativePath(stmt.location.sourcePath)}
-                      |${stmt.location.packageName}
-                      |${stmt.location.className}
+                      |${getRelativePath(stmt.location.sourcePath).escaped}
+                      |${stmt.location.packageName.escaped}
+                      |${stmt.location.className.escaped}
                       |${stmt.location.classType}
-                      |${stmt.location.fullClassName}
-                      |${stmt.location.methodName}
+                      |${stmt.location.fullClassName.escaped}
+                      |${stmt.location.methodName.escaped}
                       |${stmt.start}
                       |${stmt.end}
                       |${stmt.line}
-                      |${stmt.symbolName}
+                      |${stmt.symbolName.escaped}
                       |${stmt.treeName}
                       |${stmt.branch}
                       |0
                       |${stmt.ignored}
-                      |${stmt.desc}
+                      |${stmt.desc.escaped}
                       |\f
                       |""".stripMargin)
 
     writeHeader(writer)
     coverage.statements.toSeq
       .sortBy(_.id)
       .foreach(stmt => writeStatement(stmt, writer))
+
+  /** Makes a String suitable for output in the coverage statement data as a single line.
+   * Escaped characters: '\\' (backslash), '\n', '\r', '\f'
+   */
+  extension (str: String) def escaped: String =
+    val builder = StringBuilder(str.length)
+    var i = 0
+    while
+      i < str.length
+    do
+      str.charAt(i) match
+        case '\\' =>
+          builder ++= "\\\\"
+        case '\n' =>
+          builder ++= "\\n"
+        case '\r' =>
+          builder ++= "\\r"
+        case '\f' =>
+          builder ++= "\\f"
+        case c =>
+          builder += c
+      i += 1
+    end while
+    builder.result()

tests/coverage/pos/Enum.scoverage.check

@@ -84,7 +84,7 @@ Apply
 false
 0
 false
-println("Example 1: \n"+emptyList)
+println("Example 1: \\n"+emptyList)
 
 4
 Enum.scala
@@ -101,7 +101,7 @@ Apply
 false
 0
 false
-"Example 1: \n"+emptyList
+"Example 1: \\n"+emptyList
 
 5
 Enum.scala
@@ -118,7 +118,7 @@ Apply
 false
 0
 false
-println(s"${list}\n")
+println(s"${list}\\n")
 
 6
 Enum.scala
@@ -135,7 +135,7 @@ Apply
 false
 0
 false
-s"${list}\n"
+s"${list}\\n"
 
 7
 Enum.scala
@@ -169,8 +169,7 @@ Apply
 false
 0
 false
-for p <- Planet.values do
-        println(s"Your weight on $p is ${p.surfaceWeight(mass)}")
+for p <- Planet.values do\n        println(s"Your weight on $p is ${p.surfaceWeight(mass)}")
 
 9
 Enum.scala

tests/coverage/pos/Escaping.scala

@@ -0,0 +1,4 @@
+package covtest.`\n`
+
+class `\r\n\f`:
+  def `\r\n\f`(`\\`: String) = `\\`.length

tests/coverage/pos/Escaping.scoverage.check

@@ -0,0 +1,54 @@
+# Coverage data, format version: 3.0
+# Statement data:
+# - id
+# - source path
+# - package name
+# - class name
+# - class type (Class, Object or Trait)
+# - full class name
+# - method name
+# - start offset
+# - end offset
+# - line number
+# - symbol name
+# - tree name
+# - is branch
+# - invocations count
+# - is ignored
+# - description (can be multi-line)
+# '' sign
+# ------------------------------------------
+0
+Escaping.scala
+covtest.\n
+\r\n\f
+Class
+covtest.\n.\r\n\f
+\r\n\f
+69
+80
+3
+length
+Apply
+false
+0
+false
+`\\\\`.length
+
+1
+Escaping.scala
+covtest.\n
+\r\n\f
+Class
+covtest.\n.\r\n\f
+\r\n\f
+40
+48
+3
+\r\n\f
+DefDef
+false
+0
+false
+def `\\r\\
+

tests/coverage/pos/For.scoverage.check

@@ -33,8 +33,7 @@ Apply
 false
 0
 false
-for i <- 1 to 10 do
-    println(i)
+for i <- 1 to 10 do\n    println(i)
 
 1
 For.scala
@@ -136,8 +135,7 @@ Apply
 false
 0
 false
-for j <- 1 to 10 if f(j) do
-    println(j)
+for j <- 1 to 10 if f(j) do\n    println(j)
 
 7
 For.scala

tests/coverage/run/erased/test.scoverage.check

@@ -203,6 +203,5 @@ DefDef
 false
 0
 false
-@main
-def Test
+@main\ndef Test
 

tests/coverage/run/inheritance/test.scoverage.check

@@ -135,6 +135,5 @@ DefDef
 false
 0
 false
-@main
-def Test
+@main\ndef Test
 

tests/coverage/run/inline-def/test.scoverage.check

@@ -169,6 +169,5 @@ DefDef
 false
 0
 false
-@main
-def Test
+@main\ndef Test
 

tests/coverage/run/interpolation/test.scoverage.check

@@ -288,7 +288,7 @@ Apply
 false
 0
 false
-println(raw"a\nb")
+println(raw"a\\nb")
 
 16
 interpolation/test.scala
@@ -305,7 +305,7 @@ Apply
 false
 0
 false
-raw"a\nb"
+raw"a\\nb"
 
 17
 interpolation/test.scala