pkg: fix check-strip-compatible and generate-stripped-directory

Their semantics assume all directory `path-string?` arguments point
to existing directories in the filesystem but they do not actually
check to verify resulting in unhelpful inner exceptions
breaking the functions' semantic abstractions.

Fixed by adding appropriate checks.

Test cases included too.

Documentation updated to reflect the requirement for paths to
refer to existing directories.

Also added note that `generate-stripped-directory` does not
compile or render source files.

pkgs/racket-doc/pkg/scribblings/strip.scrbl

@@ -215,19 +215,21 @@ with the same file/directory omissions and updates as
 @command-ref{create}.}
 
 @defproc[(generate-stripped-directory [mode (or/c 'source 'binary 'binary-lib 'built)]
-                                      [src-dir path-string?]
-                                      [dest-dir path-string?])
+                                      [src-dir (and/c path-string? directory-exists?)]
+                                      [dest-dir (and/c path-string? directory-exists?)])
           void?]{
 
 Copies @racket[src-dir] to @racket[dest-dir] with file/directory
-omissions and updates corresponding the creation of a @tech{source
+omissions and updates corresponding to the creation of a @tech{source
 package}, @tech{binary package}, @tech{binary library package}, or @tech{built package} as indicated
-by @racket[mode].}
+by @racket[mode].} Note, @racket[generate-stripped-directory] does not compile or render source files
+found in the @racket[src-dir]. To perform precompilation or rendering before stripping the source directory,
+use @command-ref{setup} or @command-ref{make}.
 
 
 @defproc[(check-strip-compatible [mode (or/c 'source 'binary 'binary-lib 'built)]
                                  [pkg-name string?]
-                                 [dir path-string?]
+                                 [dir (and/c path-string? directory-exists?)]
                                  [error (string? . -> . any)])
           any]{
 

pkgs/racket-test/tests/pkg/test.rkt

@@ -61,7 +61,9 @@
    "raco"
    "binary"
    "catalogs"
-   "failure"))
+   "failure"
+
+   "api"))
 
 (module+ test
   (module config info

pkgs/racket-test/tests/pkg/tests-api.rkt

@@ -0,0 +1,50 @@
+#lang racket/base
+(require rackunit
+         racket/file
+         pkg/strip
+         "util.rkt")
+
+(this-test-is-run-by-the-main-test)
+
+(pkg-tests
+
+ (parameterize ([current-directory test-source-directory])
+   (define tmp-dir (path->directory-path (make-temporary-file "tmp~a" 'directory)))
+   (define pkg-path (build-path "test-pkgs" "pkg-strip"))
+   (define pkg-dest-path (build-path tmp-dir "pkg-strip"))
+   (make-directory pkg-dest-path)
+
+   ;; Giving path to nonexistent directory should raise a contract exception.
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (check-strip-compatible 'source "pkg-strip" "does not exist" error)))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (check-strip-compatible 'binary "pkg-strip" "does not exist" error)))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (check-strip-compatible 'binary-lib "pkg-strip" "does not exist" error)))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (check-strip-compatible 'built "pkg-strip" "does not exist" error)))
+
+   ;; Path to existing directory should succeed.
+   (check-not-exn (lambda () (check-strip-compatible 'source "pkg-strip" pkg-path error)))
+
+   ;; Giving path to nonexistent src directory should raise a contract exception.
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'source 5 pkg-dest-path)))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'binary "does not exist" pkg-dest-path)))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'binary-lib "does not exist" pkg-dest-path)))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'built "does not exist" pkg-dest-path)))
+
+   ;; Giving path to nonexistent dest directory should raise a contract exception.
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'source pkg-path "does not exist")))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'binary pkg-path "does not exist")))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'binary-lib pkg-path "does not exist")))
+
+   (check-exn #rx"expected: \\(and/c path-string\\? directory-exists\\?\\)" (lambda () (generate-stripped-directory 'built pkg-path "does not exist")))
+
+   ;; Paths to existing src and dest directories should succeed.
+   (check-not-exn (lambda () (generate-stripped-directory 'source pkg-path pkg-dest-path)))
+
+   ))

racket/collects/pkg/strip.rkt

@@ -21,6 +21,12 @@
 (define strip-binary-compile-info (make-parameter #t))
 
 (define (check-strip-compatible mode pkg dir error)
+  (unless (and (path-string? dir) (directory-exists? dir))
+    (raise-argument-error
+     'check-strip-compatible
+     "(and/c path-string? directory-exists?)"
+     dir))
+
   (define i (get-info/full dir))
   (define raw-status (and i
                           (i 'package-content-state (lambda () #f))))
@@ -58,6 +64,18 @@
 
 (define (generate-stripped-directory mode dir dest-dir
                                      #:check-status? [check-status? #t])
+  (unless (and (path-string? dir) (directory-exists? dir))
+    (raise-argument-error
+     'generate-stripped-directory
+     "(and/c path-string? directory-exists?)"
+     dir))
+
+  (unless (and (path-string? dest-dir) (directory-exists? dest-dir))
+    (raise-argument-error
+     'generate-stripped-directory
+     "(and/c path-string? directory-exists?)"
+     dest-dir))
+
   (define drop-keep-ns (make-base-namespace))
   (define (add-drop+keeps dir base drops keeps)
     (define get-info (get-info/full dir #:namespace drop-keep-ns))