In software development, after I perform a number of tests on a program, is it grammatically correct to say "testing passed" (or failed)? It is probably correct to say "testing is completed", but it doesn't tell anything about the outcome.
It's common to say "Testing passed" or "testing failed". I don't think anyone would question this.
It's not a complete, grammatically correct sentence. What you really mean, I presume, is, "The software passed the tests." If we tried to read "testing passed" as a complete sentence, we'd have to conclude that "testing" is the subject and "passed" is the verb, that is, the "testing" has "passed" something. Which isn't what we mean at all. The testing hasn't passed; the software has passed.
You could phrase it as a passive: "Testing is passed." It that case the actual actor is unspecified, but in context we'd understand that to be "the software".
But as I say, people use sentence fragments all the time, in both formal and informal contexts. As long as everyone knows from context that you're talking about software testing, "Testing passed" conveys the desired meaning.
As @Jay's answer mentions, it is not likely "Testing passed" or "Testing failed" would cause any confusion in their intended meanings. But, I don't think "Testing passed" sounds better than "Testing successful". "Testing unsuccessful" could be used for "Testing failed".
Both phrases (testing successful and testing unsuccessful) are broadly used when you are referring to any test.
are understandable and may be used to mean
to describe the entire testing process and the actual tests.
might be used after the test suite has been run to describe the tests themselves.
Testing usually consists of two parts: 1) the framework; and 2) the individual tests. For example, in Rails, the framework would be: spec; rspec; or minitest; and the tests are files using the *_spec.rb suffix.