Nodejs學習筆記——Assert（斷言）

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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)

assert.fail(a, e, m, o)

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,"","+")

assert(v, [m]), assert.ok(v, [m])

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 == true" if it‘s omited.

e.g assert(0) and assert.ok(0,"Throws me")

assert.equal(a, e, [m])

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")

assert.notEqual(a, e, [m])

Tests shallow, coercive non-equality with the not equal comparison operator ( != ).

Note: 綜上，是對比結果為false時拋出異常。

assert.deepEqual(a, e, [m])

Tests for deep equality.

Note: 不清楚！

assert.notDeepEqual(a, e, [m])

Tests for any deep inequality.

Note: 不清楚！

assert.strictEqual(a, e, [m])

Tests strict equality, as determined by the strict equality operator ( === )

 

assert.notStrictEqual(a, e, [m])

Tests strict non-equality, as determined by the strict not equal operator ( !== )

 

assert.throws(b, [error], [m])

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");

assert.doesNotThrow(b, [m])

Expects block not to throw an error, see assert.throws for details.

 

assert.ifError(v)

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學習筆記——Assert（斷言）