test(nix/utils): unit test path predicates r/2858

Change-Id: I85f38ef8f284c4accd1ea744f61358622785358d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3534
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>

8 files changed, 69 insertions, 0 deletions

diff --git a/nix/utils/tests/.skip-subtree b/nix/utils/tests/.skip-subtree
new file mode 100644
index 0000000000..1efb1b9476
--- /dev/null
+++ b/nix/utils/tests/.skip-subtree
@@ -0,0 +1 @@
+subdirectories are just test cases
diff --git a/nix/utils/tests/default.nix b/nix/utils/tests/default.nix
new file mode 100644
index 0000000000..d8f38fde5c
--- /dev/null
+++ b/nix/utils/tests/default.nix
@@ -0,0 +1,63 @@
+{ depot, lib, ... }:
+
+let
+  inherit (depot.nix.runTestsuite)
+    runTestsuite
+    it
+    assertEq
+    assertThrows
+    assertDoesNotThrow
+    ;
+
+  inherit (depot.nix.utils)
+    isDirectory
+    isRegularFile
+    isSymlink
+    ;
+
+  assertUtilsPred = msg: act: exp: [
+    (assertDoesNotThrow "${msg} does not throw" act)
+    (assertEq msg (builtins.tryEval act).value exp)
+  ];
+
+  pathPredicates = it "judges paths correctly" (lib.flatten [
+    # isDirectory
+    (assertUtilsPred "directory isDirectory"
+      (isDirectory ./directory) true)
+    (assertUtilsPred "symlink not isDirectory"
+      (isDirectory ./symlink-directory) false)
+    (assertUtilsPred "file not isDirectory"
+      (isDirectory ./directory/file) false)
+    # isRegularFile
+    (assertUtilsPred "file isRegularFile"
+      (isRegularFile ./directory/file) true)
+    (assertUtilsPred "symlink not isRegularFile"
+      (isRegularFile ./symlink-file) false)
+    (assertUtilsPred "directory not isRegularFile"
+      (isRegularFile ./directory) false)
+    # isSymlink
+    (assertUtilsPred "symlink to file isSymlink"
+      (isSymlink ./symlink-file) true)
+    (assertUtilsPred "symlink to directory isSymlink"
+      (isSymlink ./symlink-directory) true)
+    (assertUtilsPred "symlink to symlink isSymlink"
+      (isSymlink ./symlink-symlink-file) true)
+    (assertUtilsPred "symlink to missing file isSymlink"
+      (isSymlink ./missing) true)
+    (assertUtilsPred "directory not isSymlink"
+      (isSymlink ./directory) false)
+    (assertUtilsPred "file not isSymlink"
+      (isSymlink ./directory/file) false)
+    # missing files throw
+    (assertThrows "isDirectory throws on missing file"
+      (isDirectory ./does-not-exist))
+    (assertThrows "isRegularFile throws on missing file"
+      (isRegularFile ./does-not-exist))
+    (assertThrows "isSymlink throws on missing file"
+      (isSymlink ./does-not-exist))
+  ]);
+in
+
+runTestsuite "nix.utils" [
+  pathPredicates
+]
diff --git a/nix/utils/tests/directory/file b/nix/utils/tests/directory/file
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/nix/utils/tests/directory/file
diff --git a/nix/utils/tests/missing b/nix/utils/tests/missing
new file mode 120000
index 0000000000..cfa0a46515
--- /dev/null
+++ b/nix/utils/tests/missing
@@ -0,0 +1 @@
+does-not-exist
\ No newline at end of file
diff --git a/nix/utils/tests/symlink-directory b/nix/utils/tests/symlink-directory
new file mode 120000
index 0000000000..6d0450cc24
--- /dev/null
+++ b/nix/utils/tests/symlink-directory
@@ -0,0 +1 @@
+directory
\ No newline at end of file
diff --git a/nix/utils/tests/symlink-file b/nix/utils/tests/symlink-file
new file mode 120000
index 0000000000..cd5d01792a
--- /dev/null
+++ b/nix/utils/tests/symlink-file
@@ -0,0 +1 @@
+directory/file
\ No newline at end of file
diff --git a/nix/utils/tests/symlink-symlink-directory b/nix/utils/tests/symlink-symlink-directory
new file mode 120000
index 0000000000..5d6ba5247e
--- /dev/null
+++ b/nix/utils/tests/symlink-symlink-directory
@@ -0,0 +1 @@
+symlink-directory
\ No newline at end of file
diff --git a/nix/utils/tests/symlink-symlink-file b/nix/utils/tests/symlink-symlink-file
new file mode 120000
index 0000000000..f8d9ce3659
--- /dev/null
+++ b/nix/utils/tests/symlink-symlink-file
@@ -0,0 +1 @@
+symlink-file
\ No newline at end of file