Compare complex item values when preparing diff

The diffing algorithm should only recurse when the values are (shallow) equal. Fixes #32.
concordancejs · Jul 13, 2017 · 221c11e · 221c11e
1 parent f127100
commit 221c11e
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diff --git a/lib/metaDescriptors/item.js b/lib/metaDescriptors/item.js
@@ -132,7 +132,8 @@ class ComplexItem {
       }
     }
 
-    const mustRecurse = this.tag === complexTag && initialExpected.tag === complexTag
+    const mustRecurse = this.tag === complexTag && initialExpected.tag === complexTag &&
+      this.value.compare(initialExpected.value) !== UNEQUAL
     return {
       mustRecurse,
       isUnequal: !mustRecurse,

diff --git a/test/diff.js b/test/diff.js
@@ -105,6 +105,26 @@ test('diffs diverging complex types', t => {
       map([1, {foo: 'bar'}, 2]),
       map([1, {baz: 'qux'}, 2]))
     t.snapshot(actual2)
+
+    class Foo {
+      constructor () {
+        this.foo = 'foo'
+      }
+    }
+    class Bar {
+      constructor () {
+        this.bar = 'bar'
+      }
+    }
+    const actual3 = diff(
+      map([new Foo()]),
+      map([new Bar()]))
+    t.snapshot(actual3)
+
+    const actual4 = diff(
+      map([Buffer.alloc(0)]),
+      map([new Uint8Array()]))
+    t.snapshot(actual4)
   }
   test('diffs arrays', equalLength, mapArray)
   test('diffs arguments', equalLength, mapArguments)

diff --git a/test/snapshots/diff.js.md b/test/snapshots/diff.js.md
@@ -465,6 +465,24 @@ Generated by [AVA](https://ava.li).
     %diffGutters.padding#  %  %number.open%2%number.close%%item.after#,%␊
     %diffGutters.padding#  %%list.closeBracket#]%`
 
+> Snapshot 3
+
+    `%diffGutters.padding#  %%object.ctor.open%Arguments%object.ctor.close% %list.openBracket#[%␊
+    %diffGutters.actual#- %  %object.ctor.open%Foo%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.actual#- %    foo%property.separator#: %%string.line.open#'%%string.open%foo%string.close%%string.line.close#'%%property.after#,%␊
+    %diffGutters.actual#- %  %object.closeBracket#}%%item.after#,%␊
+    %diffGutters.expected#+ %  %object.ctor.open%Bar%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.expected#+ %    bar%property.separator#: %%string.line.open#'%%string.open%bar%string.close%%string.line.close#'%%property.after#,%␊
+    %diffGutters.expected#+ %  %object.closeBracket#}%%item.after#,%␊
+    %diffGutters.padding#  %%list.closeBracket#]%`
+
+> Snapshot 4
+
+    `%diffGutters.padding#  %%object.ctor.open%Arguments%object.ctor.close% %list.openBracket#[%␊
+    %diffGutters.actual#- %  %object.ctor.open%Buffer%object.ctor.close% %object.secondaryStringTag.open#@%Uint8Array%object.secondaryStringTag.close% %list.openBracket#[%%list.closeBracket#]%%item.after#,%␊
+    %diffGutters.expected#+ %  %object.ctor.open%Uint8Array%object.ctor.close% %list.openBracket#[%%list.closeBracket#]%%item.after#,%␊
+    %diffGutters.padding#  %%list.closeBracket#]%`
+
 ## diffs arrays
 
 > Snapshot 1
@@ -487,6 +505,24 @@ Generated by [AVA](https://ava.li).
     %diffGutters.padding#  %  %number.open%2%number.close%%item.after#,%␊
     %diffGutters.padding#  %%list.closeBracket#]%`
 
+> Snapshot 3
+
+    `%diffGutters.padding#  %%list.openBracket#[%␊
+    %diffGutters.actual#- %  %object.ctor.open%Foo%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.actual#- %    foo%property.separator#: %%string.line.open#'%%string.open%foo%string.close%%string.line.close#'%%property.after#,%␊
+    %diffGutters.actual#- %  %object.closeBracket#}%%item.after#,%␊
+    %diffGutters.expected#+ %  %object.ctor.open%Bar%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.expected#+ %    bar%property.separator#: %%string.line.open#'%%string.open%bar%string.close%%string.line.close#'%%property.after#,%␊
+    %diffGutters.expected#+ %  %object.closeBracket#}%%item.after#,%␊
+    %diffGutters.padding#  %%list.closeBracket#]%`
+
+> Snapshot 4
+
+    `%diffGutters.padding#  %%list.openBracket#[%␊
+    %diffGutters.actual#- %  %object.ctor.open%Buffer%object.ctor.close% %object.secondaryStringTag.open#@%Uint8Array%object.secondaryStringTag.close% %list.openBracket#[%%list.closeBracket#]%%item.after#,%␊
+    %diffGutters.expected#+ %  %object.ctor.open%Uint8Array%object.ctor.close% %list.openBracket#[%%list.closeBracket#]%%item.after#,%␊
+    %diffGutters.padding#  %%list.closeBracket#]%`
+
 ## diffs boxed primitives with extra properties
 
 > Snapshot 1
@@ -1007,6 +1043,24 @@ Generated by [AVA](https://ava.li).
     %diffGutters.padding#  %  %number.open%2%number.close%%item.after#,%␊
     %diffGutters.padding#  %%object.closeBracket#}%`
 
+> Snapshot 3
+
+    `%diffGutters.padding#  %%object.ctor.open%Set%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.actual#- %  %object.ctor.open%Foo%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.actual#- %    foo%property.separator#: %%string.line.open#'%%string.open%foo%string.close%%string.line.close#'%%property.after#,%␊
+    %diffGutters.actual#- %  %object.closeBracket#}%%item.after#,%␊
+    %diffGutters.expected#+ %  %object.ctor.open%Bar%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.expected#+ %    bar%property.separator#: %%string.line.open#'%%string.open%bar%string.close%%string.line.close#'%%property.after#,%␊
+    %diffGutters.expected#+ %  %object.closeBracket#}%%item.after#,%␊
+    %diffGutters.padding#  %%object.closeBracket#}%`
+
+> Snapshot 4
+
+    `%diffGutters.padding#  %%object.ctor.open%Set%object.ctor.close% %object.openBracket#{%␊
+    %diffGutters.actual#- %  %object.ctor.open%Buffer%object.ctor.close% %object.secondaryStringTag.open#@%Uint8Array%object.secondaryStringTag.close% %list.openBracket#[%%list.closeBracket#]%%item.after#,%␊
+    %diffGutters.expected#+ %  %object.ctor.open%Uint8Array%object.ctor.close% %list.openBracket#[%%list.closeBracket#]%%item.after#,%␊
+    %diffGutters.padding#  %%object.closeBracket#}%`
+
 ## diffs single line strings
 
 > Snapshot 1

diff --git a/test/snapshots/diff.js.snap b/test/snapshots/diff.js.snap