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2021-04-28 16:49:39 +02:00
The TypeScript compiler automatically casts a variable to the relevant type inside conditionals where it is possible to infer the type (because ``++typeof++``, ``++instanceof++``, etc was used). This compiler feature makes casts and not-``++null++`` assertions unnecessary.
2021-04-28 16:49:39 +02:00
== Noncompliant Code Example
----
function getName(x?: string | UserName) {
if (x) {
console.log("Getting name for " + x!); // Noncompliant
if (typeof x === "string")
return (x as string); // Noncompliant
else
return (x as UserName).name; // Noncompliant
}
return "NoName";
}
----
2021-04-28 16:49:39 +02:00
== Compliant Solution
----
function getName(x?: string | UserName) {
if (x) {
console.log("Getting name for " + x);
if (typeof x === "string")
return x;
else
return x.name;
}
return "NoName";
}
----