Show evaluated expr when @test isequal(...) fails

NEWS.md

@@ -79,6 +79,9 @@ Library improvements
 
   * Added `unique!` which is an inplace version of `unique` ([#20549]).
 
+  * `@test isequal(x, y)` and `@test isapprox(x, y)` now prints an evaluated expression when
+    the test fails ([#22296]).
+
 Compiler/Runtime improvements
 -----------------------------
 

base/test.jl

@@ -76,7 +76,7 @@ function Base.show(io::IO, t::Pass)
     if t.test_type == :test_throws
         # The correct type of exception was thrown
         print(io, "\n      Thrown: ", typeof(t.value))
-    elseif t.test_type == :test && isa(t.data,Expr) && t.data.head == :comparison
+    elseif t.test_type == :test && isa(t.data, Expr)
         # The test was an expression, so display the term-by-term
         # evaluated version as well
         print(io, "\n   Evaluated: ", t.data)
@@ -106,7 +106,7 @@ function Base.show(io::IO, t::Fail)
         # An exception was expected, but no exception was thrown
         print(io, "\n    Expected: ", t.data)
         print(io, "\n  No exception thrown")
-    elseif t.test_type == :test && isa(t.data,Expr) && t.data.head == :comparison
+    elseif t.test_type == :test && isa(t.data, Expr)
         # The test was an expression, so display the term-by-term
         # evaluated version as well
         print(io, "\n   Evaluated: ", t.data)
@@ -188,20 +188,31 @@ struct Threw <: ExecutionResult
     backtrace
 end
 
-function eval_comparison(evaluated::Expr, quoted::Expr)
+function eval_test(evaluated::Expr, quoted::Expr)
     res = true
     i = 1
     args = evaluated.args
     quoted_args = quoted.args
     n = length(args)
-    while i < n
-        a, op, b = args[i], args[i+1], args[i+2]
-        if res
-            res = op(a, b) === true  # Keep `res` type stable
+    if evaluated.head == :comparison
+        while i < n
+            a, op, b = args[i], args[i+1], args[i+2]
+            if res
+                res = op(a, b) === true  # Keep `res` type stable
+            end
+            quoted_args[i] = a
+            quoted_args[i+2] = b
+            i += 2
+        end
+
+    elseif evaluated.head == :call
+        op = args[1]
+        res = op(args[2:n]...) === true
+        for i in 2:n
+            quoted_args[i] = args[i]
         end
-        quoted_args[i] = a
-        quoted_args[i+2] = b
-        i += 2
+    else
+        throw(ArgumentError("Unhandled expression type: $(evaluated.head)"))
     end
     Returned(res, quoted)
 end
@@ -307,10 +318,17 @@ function get_test_result(ex)
         # pass all terms of the comparison to `eval_comparison`, as an Expr
         escaped_terms = [esc(arg) for arg in ex.args]
         quoted_terms = [QuoteNode(arg) for arg in ex.args]
-        testret = :(eval_comparison(
+        testret = :(eval_test(
             Expr(:comparison, $(escaped_terms...)),
             Expr(:comparison, $(quoted_terms...)),
         ))
+    elseif isa(ex, Expr) && ex.head == :call && ex.args[1] in (:isequal, :isapprox)
+        escaped_terms = [esc(arg) for arg in ex.args]
+        quoted_terms = [QuoteNode(arg) for arg in ex.args]
+        testret = :(eval_test(
+            Expr(:call, $(escaped_terms...)),
+            Expr(:call, $(quoted_terms...)),
+        ))
     else
         testret = :(Returned($(esc(ex)), nothing))
     end

test/test.jl

@@ -11,6 +11,10 @@
 let g = Int[], f = (x) -> (push!(g, x); x)
     @test f(1) == 1
     @test g == [1]
+
+    empty!(g)
+    @test isequal(f(2), 2)
+    @test g == [2]
 end
 
 # Test @test_broken with fail
@@ -74,6 +78,10 @@ fails = @testset NoThrowTestSet begin
     @test 1+0 == 2+0 == 3+0
     # Fail - comparison call
     @test ==(1 - 2, 2 - 1)
+    # Fail - isequal
+    @test isequal(0 / 0, 1 / 0)
+    # Fail - isapprox
+    @test isapprox(0 / 1, -1 / 0)
     # Error - unexpected pass
     @test_broken true
 end
@@ -106,6 +114,14 @@ str = sprint(show, fails[6])
 @test contains(str, "Evaluated: -1 == 1")
 
 str = sprint(show, fails[7])
+@test contains(str, "Expression: isequal(0 / 0, 1 / 0)")
+@test contains(str, "Evaluated: isequal(NaN, Inf)")
+
+str = sprint(show, fails[8])
+@test contains(str, "Expression: isapprox(0 / 1, -1 / 0)")
+@test contains(str, "Evaluated: isapprox(0.0, -Inf)")
+
+str = sprint(show, fails[9])
 @test contains(str, "Unexpected Pass")
 @test contains(str, "Expression: true")