diff --git a/tests/diff.carp b/tests/diff.carp
index 8f42bc2..531737f 100644
--- a/tests/diff.carp
+++ b/tests/diff.carp
@@ -169,12 +169,12 @@ lines")) "line-diff of identical strings is all equal")
       &(Diff.eq &(char-diff "hello" "hello"))
       "char-diff of identical strings is all equal")
 
-    (assert-equal test &(String.concat &[@"@@ -1,3 +1,3 @@
-" @" line1
-" @"+changed
-" @"-line2
-" @" line3
-"]) &(unified &(line-diff "line1
+    (assert-equal test "@@ -1,3 +1,3 @@
+ line1
++changed
+-line2
+ line3
+" &(unified &(line-diff "line1
 line2
 line3" "line1
 changed
@@ -182,46 +182,46 @@ line3")) "unified renders single-hunk diff with correct header")
     (assert-equal test "" &(unified &(line-diff "same
 text" "same
 text")) "unified of identical strings is empty")
-    (assert-equal test &(String.concat &[@"@@ -1,4 +1,4 @@
-" @"+new
-" @"-old
-" @" a
-" @" b
-" @" c
-"]) &(unified &(line-diff "old
+    (assert-equal test "@@ -1,4 +1,4 @@
++new
+-old
+ a
+ b
+ c
+" &(unified &(line-diff "old
 a
 b
 c" "new
 a
 b
 c")) "unified handles change at start")
-    (assert-equal test &(String.concat &[@"@@ -1,4 +1,4 @@
-" @" a
-" @" b
-" @" c
-" @"+new
-" @"-old
-"]) &(unified &(line-diff "a
+    (assert-equal test "@@ -1,4 +1,4 @@
+ a
+ b
+ c
++new
+-old
+" &(unified &(line-diff "a
 b
 c
 old" "a
 b
 c
 new")) "unified handles change at end")
-    (assert-equal test &(String.concat &[@"@@ -1,5 +1,5 @@
-" @" a
-" @"+BB
-" @"-b
-" @" c
-" @" d
-" @" e
-" @"@@ -8,4 +8,4 @@
-" @" h
-" @" i
-" @" j
-" @"+KK
-" @"-k
-"]) &(unified &(line-diff "a
+    (assert-equal test "@@ -1,5 +1,5 @@
+ a
++BB
+-b
+ c
+ d
+ e
+@@ -8,4 +8,4 @@
+ h
+ i
+ j
++KK
+-k
+" &(unified &(line-diff "a
 b
 c
 d
@@ -329,20 +329,20 @@ KK")) "unified generates multiple hunks for distant changes")
       "str of Insertion with multiple elements")
 
     ; unified-with-context
-    (assert-equal test &(String.concat &[@"@@ -2,1 +2,1 @@
-" @"+changed
-" @"-line2
-"]) &(unified-with-context &(line-diff "line1
+    (assert-equal test "@@ -2,1 +2,1 @@
++changed
+-line2
+" &(unified-with-context &(line-diff "line1
 line2
 line3" "line1
 changed
 line3") 0) "unified-with-context 0 omits context lines")
-    (assert-equal test &(String.concat &[@"@@ -1,3 +1,3 @@
-" @" line1
-" @"+changed
-" @"-line2
-" @" line3
-"]) &(unified-with-context &(line-diff "line1
+    (assert-equal test "@@ -1,3 +1,3 @@
+ line1
++changed
+-line2
+ line3
+" &(unified-with-context &(line-diff "line1
 line2
 line3" "line1
 changed
@@ -356,17 +356,17 @@ line2
 line3" "line1
 changed
 line3") 3) "unified-with-context 3 is identical to unified")
-    (assert-equal test &(String.concat &[@"@@ -1,3 +1,3 @@
-" @" a
-" @"+BB
-" @"-b
-" @" c
-" @"@@ -5,3 +5,3 @@
-" @" e
-" @"+FF
-" @"-f
-" @" g
-"]) &(unified-with-context &(line-diff "a
+    (assert-equal test "@@ -1,3 +1,3 @@
+ a
++BB
+-b
+ c
+@@ -5,3 +5,3 @@
+ e
++FF
+-f
+ g
+" &(unified-with-context &(line-diff "a
 b
 c
 d