From 7fa2496a66a153751f46a213b19377d2dfd0678d Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Thu, 22 Jun 2017 17:27:40 -0700
Subject: [PATCH] next: unit tests for restructure

---
 pitfall/restructure/array-test.rkt | 82 ++++++++++++++++++++++++++++++
 pitfall/restructure/pointer.rkt    |  6 ++-
 pitfall/restructure/struct.rkt     |  3 +-
 3 files changed, 89 insertions(+), 2 deletions(-)
 create mode 100644 pitfall/restructure/array-test.rkt

diff --git a/pitfall/restructure/array-test.rkt b/pitfall/restructure/array-test.rkt
new file mode 100644
index 00000000..1da38843
--- /dev/null
+++ b/pitfall/restructure/array-test.rkt
@@ -0,0 +1,82 @@
+#lang restructure/racket
+(require "array.rkt" "stream.rkt" "number.rkt" rackunit)
+
+#|
+approximates
+https://github.com/mbutterick/restructure/blob/master/test/Array.coffee
+|#
+
+;; it 'should decode fixed length', ->
+(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+      [array (+Array uint8 4)])
+  (check-equal? (send array decode stream) '(1 2 3 4)))
+
+;; todo
+;; it 'should decode fixed amount of bytes', ->
+#;(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+        [array (+Array uint16be 4 'bytes)])
+    (check-equal? (send array decode stream) '(258 772)))
+
+;; todo
+;; it 'should decode length from parent key', ->
+#;(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+        [array (+Array uint8 4 'len)])
+    (check-equal? (send array decode stream (mhash 'len 4)) '(1 2 3 4)))
+
+;; todo
+;; it 'should decode amount of bytes from parent key', ->
+#;(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+        [array (+Array uint16be 'len 'bytes)])
+    (check-equal? (send array decode stream (mhash 'len 4)) '(258 772)))
+
+
+;; todo
+;; it 'should decode length as number before array', ->
+#;(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+        [array (+Array uint8 uint8)])
+    (check-equal? (send array decode stream (mhash 'len 4)) '(1 2 3 4)))
+
+
+;; todo
+;; it 'should decode amount of bytes as number before array', ->
+#;(let ([stream (+DecodeStream (bytes 4 1 2 3 4 5))]
+        [array (+Array uint16be uint8 'bytes)])
+    (check-equal? (send array decode stream) '(258 772)))
+
+;; it 'should decode length from function', ->
+(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+      [array (+Array uint8 (λ _ 4))])
+  (check-equal? (send array decode stream) '(1 2 3 4)))
+
+;; todo
+;; it 'should decode amount of bytes from function', ->
+#;(let ([stream (+DecodeStream (bytes 4 1 2 3 4 5))]
+        [array (+Array uint16be (λ _ 4) 'bytes)])
+    (check-equal? (send array decode stream) '(258 772)))
+
+;; todo
+;; it 'should decode to the end of the parent if no length is given', ->
+#;(let ([stream (+DecodeStream (bytes 1 2 3 4 5))]
+        [array (+Array uint8)])
+    (check-equal? (send array decode stream (mhash '_length 4 '_startOffset 0)) '(1 2 3 4)))
+
+
+;; it 'should decode to the end of the stream if no parent and length is given', ->
+(let ([stream (+DecodeStream (bytes 1 2 3 4))]
+      [array (+Array uint8)])
+  (check-equal? (send array decode stream) '(1 2 3 4)))
+
+
+;; it 'should use array length', ->
+(let ([array (+Array uint8 10)])
+  (check-equal? (send array size '(1 2 3 4)) 4))
+
+;; todo
+;; it 'should add size of length field before string', ->
+#;(let ([array (+Array uint8 uint8)])
+  (check-equal? (send array size '(1 2 3 4)) 5))
+
+
+;; it 'should use defined length if no value given', ->
+(let ([array (+Array uint8 10)])
+  (check-equal? (send array size) 10))
\ No newline at end of file
diff --git a/pitfall/restructure/pointer.rkt b/pitfall/restructure/pointer.rkt
index 280bb915..7a3a325b 100644
--- a/pitfall/restructure/pointer.rkt
+++ b/pitfall/restructure/pointer.rkt
@@ -17,7 +17,11 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
     (define offset (send offsetType decode stream ctx))
     (report scope 'pointer-scope)
     (define relative (caseq scope
-                            [(local) (or (· ctx res _startOffset) (· ctx _startOffset))]
+                            [(local) (when (and (· ctx res _startOffset) (· ctx _startOffset)
+                                                (not (= (· ctx res _startOffset) (· ctx _startOffset))))
+                                       (report* ctx (· ctx res _startOffset) (· ctx _startOffset))
+                                       (error 'bazongas))
+                                     (· ctx _startOffset)]
                             [(parent) (· ctx parent _startOffset)]
                             [(immediate) (- (· stream pos) (send offsetType size))]
                             [(global) 
diff --git a/pitfall/restructure/struct.rkt b/pitfall/restructure/struct.rkt
index 67a57ced..15a46b38 100644
--- a/pitfall/restructure/struct.rkt
+++ b/pitfall/restructure/struct.rkt
@@ -52,7 +52,8 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
         (if (procedure? type)
             (type res)
             (send type decode stream this)))
-      (hash-set! res key val)))
+      (hash-set! res key val)
+      (hash-set! res '_currentOffset (- (· stream pos) (· res _startOffset)))))
 
   (define/override (size [input-hash (mhash)] [parent #f] [includePointers #t])
     (for/sum ([(key type) (in-dict fields)])