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Nodejs学习笔记——Assert(断言)
- Assert - a:actual e:expected m:message o:operator v:value b:block
- assert.fail(a, e, m, o)
- assert(v, m), assert.ok(v, [m])
- assert.equal(a, e, [m])
- assert.notEqual(a, e, [m])
- assert.deepEqual(a, e, [m])
- assert.notDeepEqual(a, e, [m])
- assert.strictEqual(a, e, [m])
- assert.notStrictEqual(a, e, [m])
- assert.throws(b, [error], [m])
- assert.doesNotThrow(b, [m])
- assert.ifError(v)
Throws an exception that displays the values for actual
and expected
separated by the provided operator.
Note: Always throws an exception and display the message which will be "actual operator expected" if it‘s omited.
e.g assert.fail(1,1,"Always throws this message","=")
and assert.fail(1,1,"","+")
Tests if value is truthy, it is equivalent to assert.equal(true, !!value, message);
Note: If the value isn‘t a truth-value, it throws and exception and display the message which will be "value =http://www.mamicode.com/= true" if it‘s omited.
e.g assert(0)
and assert.ok(0,"Throws me")
Tests shallow, coercive equality with the equal comparison operator ( ==
).
e.g assert.equal(1,2,"They are not equal")
and assert.equal(1,1,"would not show me")
Tests shallow, coercive non-equality with the not equal comparison operator ( !=
).
Note: 综上,是对比结果为false时抛出异常。
Tests for deep equality.
Note: 不清楚!
Tests for any deep inequality.
Note: 不清楚!
Tests strict equality, as determined by the strict equality operator ( ===
)
Tests strict non-equality, as determined by the strict not equal operator ( !==
)
Expects block
to throw an error. error
can be constructor, RegExp
or validation function.
Validate instanceof using constructor:
assert.throws( function() { throw new Error("Wrong value"); }, Error);
Validate error message using RegExp:
assert.throws( function() { throw new Error("Wrong value"); }, /value/);
Custom error validation:
assert.throws( function() { throw new Error("Wrong value"); }, function(err) { if ( (err instanceof Error) && /value/.test(err) ) { return true; } }, "unexpected error");
Expects block
not to throw an error, see assert.throws
for details.
Tests if value is not a false value, throws if it is a true value. Useful when testing the first argument, error
in callbacks.
Note: it throws error when the value is a truth-value!
Nodejs学习笔记——Assert(断言)