From 8bbe8fbdad81c31dc9391d47c4f86aa08e71be2f Mon Sep 17 00:00:00 2001
From: Christer van der Meeren <christer@infotech.no>
Date: Fri, 8 Sep 2023 15:07:49 +0200
Subject: [PATCH] Add AllBe

---
 src/Faqt.Tests/SeqAssertions.fs | 104 ++++++++++++++++++++++++++++++++
 src/Faqt/SeqAssertions.fs       |  31 ++++++++++
 2 files changed, 135 insertions(+)

diff --git a/src/Faqt.Tests/SeqAssertions.fs b/src/Faqt.Tests/SeqAssertions.fs
index 6996af4..3c1f3af 100644
--- a/src/Faqt.Tests/SeqAssertions.fs
+++ b/src/Faqt.Tests/SeqAssertions.fs
@@ -625,6 +625,110 @@ But was: [1, 2]
 """
 
 
+module AllBe =
+
+
+    [<Fact>]
+    let ``Can be chained with And`` () =
+        [ 1 ].Should().AllBe(1).Id<And<int list>>().And.Be([ 1 ])
+
+
+    let passData = [
+        [| box List<string>.Empty; "a" |]
+        [| [ "a" ]; "a" |]
+        [| [ "a"; "a" ]; "a" |]
+        [| [ (null: string) ]; (null: string) |]
+    ]
+
+
+    [<Theory>]
+    [<MemberData(nameof passData)>]
+    let ``Passes if all items are equal to the specified value`` (subject: seq<string>) (expected: string) =
+        subject.Should().AllBe(expected)
+
+
+    let failData = [
+        [| box<seq<string>> null; "a" |]
+        [| [ "a" ]; "b" |]
+        [| [ "a"; "b" ]; "a" |]
+        [| [ "a"; null ]; (null: string) |]
+    ]
+
+
+    [<Theory>]
+    [<MemberData(nameof failData)>]
+    let ``Fails if null or not all items are equal to the specified value`` (subject: seq<string>) (expected: string) =
+        assertFails (fun () -> subject.Should().AllBe(expected)) |> ignore
+
+
+    [<Fact>]
+    let ``Fails with expected message if only subject is null`` () =
+        fun () ->
+            let x: seq<int> = null
+            x.Should().AllBe(1)
+        |> assertExnMsg
+            """
+Subject: x
+Should: AllBe
+Expected: 1
+But was: null
+"""
+
+
+    [<Fact>]
+    let ``Fails with expected message with because if only subject is null`` () =
+        fun () ->
+            let x: seq<int> = null
+            x.Should().AllBe(1, "Some reason")
+        |> assertExnMsg
+            """
+Subject: x
+Because: Some reason
+Should: AllBe
+Expected: 1
+But was: null
+"""
+
+
+    [<Fact>]
+    let ``Fails with expected message if items are not equal`` () =
+        fun () ->
+            let x = [ 1; 3; 2 ]
+            x.Should().AllBe(3)
+        |> assertExnMsg
+            """
+Subject: x
+Should: AllBe
+Expected: 3
+Failures:
+- Index: 0
+  Value: 1
+- Index: 2
+  Value: 2
+Subject value: [1, 3, 2]
+"""
+
+
+    [<Fact>]
+    let ``Fails with expected message with because if items are not equal`` () =
+        fun () ->
+            let x = [ 1; 3; 2 ]
+            x.Should().AllBe(3, "Some reason")
+        |> assertExnMsg
+            """
+Subject: x
+Because: Some reason
+Should: AllBe
+Expected: 3
+Failures:
+- Index: 0
+  Value: 1
+- Index: 2
+  Value: 2
+Subject value: [1, 3, 2]
+"""
+
+
 module SequenceEqual =
 
 
diff --git a/src/Faqt/SeqAssertions.fs b/src/Faqt/SeqAssertions.fs
index ffb18ef..765815c 100644
--- a/src/Faqt/SeqAssertions.fs
+++ b/src/Faqt/SeqAssertions.fs
@@ -213,6 +213,37 @@ type SeqAssertions =
         And(t)
 
 
+    /// Asserts that all items in the subject are equal to the specified value.
+    [<Extension>]
+    static member AllBe(t: Testable<#seq<'a>>, expected: 'a, ?because) : And<_> =
+        use _ = t.Assert()
+
+        if isNull (box t.Subject) then
+            t.With("Expected", expected).With("But was", t.Subject).Fail(because)
+        else
+            let differentItems =
+                t.Subject
+                |> Seq.indexed
+                |> Seq.choose (fun (i, actualItem) ->
+                    if actualItem <> expected then
+                        Some {|
+                            Index = i
+                            Value = TryFormat actualItem
+                        |}
+                    else
+                        None
+                )
+
+            if not (Seq.isEmpty differentItems) then
+                t
+                    .With("Expected", expected)
+                    .With("Failures", differentItems)
+                    .With("Subject value", t.Subject)
+                    .Fail(because)
+
+        And(t)
+
+
     /// Asserts that the subject contains the same items in the same order as the specified sequence. Passes if both
     /// sequences are null.
     [<Extension>]