Correct @test using chained comparison

(cherry picked from commit f2805a5)
ref #22315

Revise `get_test_result` to work correctly with ≈

Escaping the ≈ operator would result in the displayed evaluated
expression appearing as `x isapprox y` instead of `x ≈ y`. Additionally,
the code was written to ensure that the arguments of `@test` are only
evaluated once.

(cherry picked from commit a7ba25b)

Update tests to check expression output

(cherry picked from commit 2a37b80)

Add test for comparison calls

(cherry picked from commit d4e2b57)

base/test.jl

@@ -186,19 +186,22 @@ struct Threw <: ExecutionResult
     backtrace
 end
 
-function eval_comparison(ex::Expr)
+function eval_comparison(evaluated::Expr, quoted::Expr)
     res = true
     i = 1
-    a = ex.args
-    n = length(a)
+    args = evaluated.args
+    quoted_args = quoted.args
+    n = length(args)
     while i < n
-        res = a[i+1](a[i], a[i+2])
-        if !isa(res,Bool) || !res
-            break
+        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
-    Returned(res, ex)
+    Returned(res, quoted)
 end
 
 const comparison_prec = Base.operator_precedence(:(==))
@@ -293,18 +296,19 @@ end
 function get_test_result(ex)
     orig_ex = Expr(:inert, ex)
     # Normalize non-dot comparison operator calls to :comparison expressions
-    if isa(ex, Expr) && ex.head == :call && length(ex.args)==3 &&
+    if isa(ex, Expr) && ex.head == :call && length(ex.args) == 3 &&
         first(string(ex.args[1])) != '.' &&
         (ex.args[1] === :(==) || Base.operator_precedence(ex.args[1]) == comparison_prec)
-        testret = :(eval_comparison(Expr(:comparison,
-                                         $(esc(ex.args[2])), $(esc(ex.args[1])), $(esc(ex.args[3])))))
-    elseif isa(ex, Expr) && ex.head == :comparison
+        ex = Expr(:comparison, ex.args[2], ex.args[1], ex.args[3])
+    end
+    if isa(ex, Expr) && ex.head == :comparison
         # pass all terms of the comparison to `eval_comparison`, as an Expr
-        terms = ex.args
-        for i = 1:length(terms)
-            terms[i] = esc(terms[i])
-        end
-        testret = :(eval_comparison(Expr(:comparison, $(terms...))))
+        escaped_terms = [esc(arg) for arg in ex.args]
+        quoted_terms = [QuoteNode(arg) for arg in ex.args]
+        testret = :(eval_comparison(
+            Expr(:comparison, $(escaped_terms...)),
+            Expr(:comparison, $(quoted_terms...)),
+        ))
     else
         testret = :(Returned($(esc(ex)), nothing))
     end

test/test.jl

@@ -7,6 +7,12 @@
 @test strip("\t  hi   \n") == "hi"
 @test strip("\t  this should fail   \n") != "hi"
 
+# @test should only evaluate the arguments once
+let g = Int[], f = (x) -> (push!(g, x); x)
+    @test f(1) == 1
+    @test g == [1]
+end
+
 # Test @test_broken with fail
 @test_broken false
 @test_broken 1 == 2
@@ -60,16 +66,46 @@ fails = @testset NoThrowTestSet begin
     @test_throws OverflowError 1 + 1
     # Fail - comparison
     @test 1+1 == 2+2
+    # Fail - approximate comparison
+    @test 1/1 ≈ 2/1
+    # Fail - chained comparison
+    @test 1+0 == 2+0 == 3+0
+    # Fail - comparison call
+    @test ==(1 - 2, 2 - 1)
     # Error - unexpected pass
     @test_broken true
 end
-for i in 1:3
+for i in 1:length(fails) - 1
     @test isa(fails[i], Base.Test.Fail)
 end
-@test contains(sprint(show, fails[1]), "Thrown: ErrorException")
-@test contains(sprint(show, fails[2]), "No exception thrown")
-@test contains(sprint(show, fails[3]), "Evaluated: 2 == 4")
-@test contains(sprint(show, fails[4]), "Unexpected Pass")
+
+str = sprint(show, fails[1])
+@test contains(str, "Expression: error()")
+@test contains(str, "Thrown: ErrorException")
+
+str = sprint(show, fails[2])
+@test contains(str, "Expression: 1 + 1")
+@test contains(str, "No exception thrown")
+
+str = sprint(show, fails[3])
+@test contains(str, "Expression: 1 + 1 == 2 + 2")
+@test contains(str, "Evaluated: 2 == 4")
+
+str = sprint(show, fails[4])
+@test contains(str, "Expression: 1 / 1 ≈ 2 / 1")
+@test contains(str, "Evaluated: 1.0 ≈ 2.0")
+
+str = sprint(show, fails[5])
+@test contains(str, "Expression: 1 + 0 == 2 + 0 == 3 + 0")
+@test contains(str, "Evaluated: 1 == 2 == 3")
+
+str = sprint(show, fails[6])
+@test contains(str, "Expression: 1 - 2 == 2 - 1")
+@test contains(str, "Evaluated: -1 == 1")
+
+str = sprint(show, fails[7])
+@test contains(str, "Unexpected Pass")
+@test contains(str, "Expression: true")
 
 # Test printing of a TestSetException
 tse_str = sprint(show, Test.TestSetException(1,2,3,4,Vector{Union{Base.Test.Error, Base.Test.Fail}}()))