Port realpath tests to littlecheck

I'm gonna add more tests to this and I don't want to touch the old stuff.

Notice that this needs to have the output of the complete_directories
test adjusted because this one now runs later.

That's something we should take into account in future.

tests/__fish_complete_directories.out

@@ -9,8 +9,6 @@ test/data/	Directory
 test/data/abc/	Directory
 test/data/abcd/	Directory
 test/data/fish/	Directory
-test/data/fish-symlink/	Directory
-test/data/fish-symlink2/	Directory
 test/data/xy/	Directory
 test/data/xyz/	Directory
 # __fish_complete_directories test/data/abc

tests/checks/realpath.fish

@@ -1,3 +1,4 @@
+# RUN: %fish %s
 # $XDG_DATA_HOME can itself be a relative path. So force it to an absolute
 # path so we can remove it from any resolved paths below. This is needed
 # because the contents of the builtin realpath.out file can't include any $PWD
@@ -7,30 +8,38 @@ set -l data_home_realpath (builtin realpath $XDG_DATA_HOME)
 # A bogus absolute path is handled correctly and sets a failure status.
 if not builtin realpath /this/better/be/an/invalid/path
     echo first invalid path handled okay
+    # CHECK: first invalid path handled okay
+    # CHECKERR: builtin realpath: /this/better/be/an/invalid/path: No such file or directory
 end
 
 # A non-existent file relative to $PWD succeeds.
 set -l real_path (builtin realpath nonexistent-file)
 if test "$real_path" = (realpath $PWD)"/nonexistent-file"
     echo nonexistent-file in PWD correctly converted
+    # CHECK: nonexistent-file in PWD correctly converted
 end
 
 # The simplest absolute path should undergo no transformation.
 builtin realpath /
+# CHECK: /
 
 # The second simplest absolute path should undergo no transformation.
 builtin realpath /this-better-not-exist
+# CHECK: /this-better-not-exist
 
 # Check that a pathological case is handled correctly (i.e., there is only one
 # leading slash).
 builtin realpath /../../x
+# CHECK: /x
 
 # Another pathological corner case. GNU realpath first strips trailing slashes
 # so that "/a//" is converted to "/a" before performing the real path
 # conversion. So, despite appearances, it considers "a" to be the last
 # component in that case.
 builtin realpath /abc/
+# CHECK: /abc
 builtin realpath /def///
+# CHECK: /def
 
 # Verify `realpath .` when cwd is a deleted directory gives a no such file or dir error.
 set -l tmpdir (mktemp -d)
@@ -39,6 +48,7 @@ pushd $tmpdir
 # But that's what we want to test, so we weasel around it.
 sh -c "cd ..; rmdir $tmpdir"
 builtin realpath .
+# CHECKERR: builtin realpath: .: No such file or directory
 popd
 
 # A single symlink to a directory is correctly resolved.
@@ -47,6 +57,7 @@ set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink)
 set -l expected_real_path "$data_home_realpath/fish"
 if test "$real_path" = "$expected_real_path"
     echo "fish-symlink handled correctly"
+    # CHECK: fish-symlink handled correctly
 else
     echo "fish-symlink not handled correctly: $real_path != $expected_real_path" >&2
 end
@@ -57,6 +68,7 @@ set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink/nonexistent-file-
 set -l expected_real_path "$data_home_realpath/fish/nonexistent-file-relative-to-a-symlink"
 if test "$real_path" = "$expected_real_path"
     echo "fish-symlink/nonexistent-file-relative-to-a-symlink correctly converted"
+    # CHECK: fish-symlink/nonexistent-file-relative-to-a-symlink correctly converted
 else
     echo "failure nonexistent-file-relative-to-a-symlink: $real_path != $expected_real_path" >&2
 end
@@ -69,6 +81,7 @@ set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink/symlink_file)
 set -l expected_real_path "$data_home_realpath/fish/real_file"
 if test "$real_path" = "$expected_real_path"
     echo "fish-symlink/symlink_file handled correctly"
+    # CHECK: fish-symlink/symlink_file handled correctly
 else
     echo "fish-symlink/symlink_file not handled correctly: $real_path != expected_real_path" >&2
 end

tests/realpath.err

@@ -1,2 +0,0 @@
-builtin realpath: /this/better/be/an/invalid/path: No such file or directory
-builtin realpath: .: No such file or directory

tests/realpath.out

@@ -1,10 +0,0 @@
-first invalid path handled okay
-nonexistent-file in PWD correctly converted
-/
-/this-better-not-exist
-/x
-/abc
-/def
-fish-symlink handled correctly
-fish-symlink/nonexistent-file-relative-to-a-symlink correctly converted
-fish-symlink/symlink_file handled correctly