Fix expecty macro (com-lihaoyi#307)

trying to fix com-lihaoyi#305

It seems that AST that our macro produces is spliced into AST of the
expression provided to Expecty.expect

Then it tries to evaluate this composed AST, but it fails, I'm not
exactly sure why, maybe some local vals in macro arent simply available
in the scope where expecty evaluates them.

I think Expecty.expect should expand only AST of expression provided to
it (and do not follow macros and splice ASTs generated by them)

This PR rewrites macro a little bit not to use values calculated in
macro itself (it also removes potentially problematic Expr.apply call).
As a consequence we have to make a segmentsFromString public, because
call to it is also inlined.

This change fixes compilation of expecty macros, but due to the fact
that expecty expands AST too much, its assertion clues will be malformed
anyway, but I don't think we would be able to solve this in os-lib.


Note:
Using scala 2 there is no bug.

Author: pawelsadlo

build.sc

@@ -24,6 +24,7 @@ object Deps {
   val geny = ivy"com.lihaoyi::geny::1.1.1"
   val sourcecode = ivy"com.lihaoyi::sourcecode::0.4.2"
   val utest = ivy"com.lihaoyi::utest::0.8.4"
+  val expecty = ivy"com.eed3si9n.expecty::expecty::0.16.0"
   def scalaReflect(scalaVersion: String) = ivy"org.scala-lang:scala-reflect:$scalaVersion"
   def scalaLibrary(version: String) = ivy"org.scala-lang:scala-library:${version}"
 }
@@ -164,6 +165,7 @@ object os extends Module {
   object jvm extends Cross[OsJvmModule](scalaVersions)
   trait OsJvmModule extends OsModule with MiMaChecks {
     object test extends ScalaTests with OsLibTestModule {
+      override def ivyDeps = T{super.ivyDeps() ++ Agg(Deps.expecty)}
 
       // we check the textual output of system commands and expect it in english
       def forkEnv = super.forkEnv() ++ Map(

os/src-3/Macros.scala

@@ -1,6 +1,6 @@
 package os
 
-import os.PathChunk.{RelPathChunk, StringPathChunk, segmentsFromStringLiteralValidation}
+import os.PathChunk.{RelPathChunk, StringPathChunk, segmentsFromString, segmentsFromStringLiteralValidation}
 import os.RelPath.fromStringSegments
 
 import scala.quoted.{Expr, Quotes}
@@ -20,11 +20,9 @@ object Macros {
 
     s.asTerm match {
       case Inlined(_, _, Literal(StringConstant(literal))) =>
-        val stringSegments = segmentsFromStringLiteralValidation(literal)
+        segmentsFromStringLiteralValidation(literal)
         '{
-          new RelPathChunk(fromStringSegments(${
-            Expr(stringSegments)
-          }))
+          new RelPathChunk(fromStringSegments(segmentsFromString($s)))
         }
       case _ =>
         '{

os/src/Path.scala

@@ -20,14 +20,14 @@ trait StringPathChunkConversion {
 }
 
 object PathChunk extends PathChunkMacros {
-  private[os] def segmentsFromString(s: String): Array[String] = {
+  def segmentsFromString(s: String): Array[String] = {
     val trailingSeparatorsCount = s.reverseIterator.takeWhile(_ == '/').length
     val strNoTrailingSeps = s.dropRight(trailingSeparatorsCount)
     val splitted = strNoTrailingSeps.split('/')
     splitted ++ Array.fill(trailingSeparatorsCount)("")
   }
 
-  private[os] def segmentsFromStringLiteralValidation(literal: String) = {
+  private[os] def segmentsFromStringLiteralValidation(literal: String): Array[String] = {
     val stringSegments = segmentsFromString(literal)
     val validSegmnts = validLiteralSegments(stringSegments)
     val sanitizedLiteral = validSegmnts.mkString("/")

os/test/src-jvm/ExpectyIntegration.scala

@@ -0,0 +1,33 @@
+package test.os
+
+import os._
+import utest._
+import com.eed3si9n.expecty.Expecty.expect
+
+object ExpectyIntegration extends TestSuite {
+  val tests = Tests {
+    test("Literals") {
+      test("Basic") {
+        expect(rel / "src" / "Main/.scala" == rel / "src" / "Main" / ".scala")
+        expect(root / "core/src/test" == root / "core" / "src" / "test")
+        expect(root / "core/src/test" == root / "core" / "src/test")
+      }
+      test("literals with [..]") {
+        expect(rel / "src" / ".." == rel / "src" / os.up)
+        expect(root / "src/.." == root / "src" / os.up)
+        expect(root / "src" / ".." == root / "src" / os.up)
+        expect(root / "hello" / ".." / "world" == root / "hello" / os.up / "world")
+        expect(root / "hello" / "../world" == root / "hello" / os.up / "world")
+        expect(root / "hello/../world" == root / "hello" / os.up / "world")
+      }
+      test("from issue") {
+        expect(Seq(os.pwd / "foo") == Seq(os.pwd / "foo"))
+        val path = os.Path("/") / "tmp" / "foo"
+        expect(path.startsWith(os.Path("/") / "tmp"))
+      }
+      test("multiple args") {
+        expect(rel / "src" / ".." == rel / "src" / os.up, root / "src/.." == root / "src" / os.up)
+      }
+    }
+  }
+}

os/test/src/PathTests.scala

@@ -21,6 +21,7 @@ object PathTests extends TestSuite {
         assert(root / "core/src/test" == root / "core" / "src/test")
       }
       test("literals with [..]") {
+
         assert(rel / "src" / ".." == rel / "src" / os.up)
         assert(root / "src/.." == root / "src" / os.up)
         assert(root / "src" / ".." == root / "src" / os.up)