iframe-proxy | Sunbelt Computer Software

87 lines (80 loc) · 2.27 KB

 * @name Missing await
 * @description Using a promise without awaiting its result can lead to unexpected behavior.
 * @kind problem
 * @problem.severity warning
 * @id js/missing-await
 * @tags quality
 *       reliability
 *       correctness
 * @precision high
import javascript
 * Holds if `call` is a call to an `async` function.
predicate isAsyncCall(DataFlow::CallNode call, boolean nullable) {
  // If a callee is known, and all known callees are async, assume all
  // possible callees are async.
  forex(Function callee | call.getACallee() = callee | callee.isAsync()) and
  if call.asExpr() instanceof OptionalUse then nullable = true else nullable = false
 * Holds if `node` is always a promise.
predicate isPromise(DataFlow::SourceNode node, boolean nullable) {
  isAsyncCall(node, nullable)
  not isAsyncCall(node, _) and
  node.asExpr().getTypeBinding().isPromiseType() and
  nullable = true
 * Holds the result of `e` is used in a way that doesn't make sense for Promise objects.
predicate isBadPromiseContext(Expr expr) {
  exists(BinaryExpr binary |
    expr = binary.getAnOperand() and
    not binary instanceof LogicalExpr and
    not binary instanceof InstanceofExpr
  expr = any(LogicalBinaryExpr e).getLeftOperand()
  exists(UnaryExpr e |
    expr = e.getOperand() and
    not e instanceof VoidExpr and
    not e instanceof DeleteExpr
  expr = any(UpdateExpr e).getOperand()
  expr = any(ConditionalExpr e).getCondition()
  expr = any(IfStmt stmt).getCondition()
  expr = any(ForInStmt stmt).getIterationDomain()
  expr = any(IndexExpr e).getIndex()
string tryGetPromiseExplanation(Expr e) {
  result = "The value '" + e.(VarAccess).getName() + "' is always a promise."
  result = "The call to '" + e.(CallExpr).getCalleeName() + "' always returns a promise."
string getPromiseExplanation(Expr e) {
  result = tryGetPromiseExplanation(e)
  not exists(tryGetPromiseExplanation(e)) and
  result = "This value is always a promise."
from Expr expr, boolean nullable
  isBadPromiseContext(expr) and
  isPromise(expr.flow().getImmediatePredecessor*(), nullable) and
    nullable = false
    expr.inNullSensitiveContext()
select expr, "Missing await. " + getPromiseExplanation(expr)

Sunbelt Computer Software

PL/B Language Development and Support

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Sunbelt Computer Software

PL/B Language Development and Support

Uh oh!

FilesExpand file tree

MissingAwait.ql

Latest commit

History

MissingAwait.ql

File metadata and controls