babel-plugin-annotate-pure-calls/dist/babel-plugin-annotate-pure-calls.esm.js

Babel plugin for annotating automatically pure function calls.

const PURE_ANNOTATION = '#__PURE__';
const isPureAnnotated = node => {
  const {
    leadingComments
  } = node;
  if (!leadingComments) {
    return false;
  }
  return leadingComments.some(comment => /[@#]__PURE__/.test(comment.value));
};
const annotateAsPure = path => {
  if (isPureAnnotated(path.node)) {
    return;
  }
  path.addComment('leading', PURE_ANNOTATION);
};
const hasCallableParent = ({
  parentPath
}) => parentPath.isCallExpression() || parentPath.isNewExpression();
const isUsedAsCallee = path => {
  if (!hasCallableParent(path)) {
    return false;
  }
  return path.parentPath.get('callee') === path;
};
const isInCallee = path => {
  do {
    path = path.parentPath;
    if (isUsedAsCallee(path)) {
      return true;
    }
  } while (!path.isStatement() && !path.isFunction());
  return false;
};
const isExecutedDuringInitialization = path => {
  let functionParent = path.getFunctionParent();
  while (functionParent) {
    if (!isUsedAsCallee(functionParent)) {
      return false;
    }
    functionParent = functionParent.getFunctionParent();
  }
  return true;
};
const isInAssignmentContext = path => {
  const statement = path.getStatementParent();
  let parentPath;
  do {
    ({
      parentPath
    } = parentPath || path);
    if (parentPath.isVariableDeclaration() || parentPath.isAssignmentExpression() || parentPath.isClass()) {
      return true;
    }
  } while (parentPath !== statement);
  return false;
};
const callableExpressionVisitor = path => {
  if (isUsedAsCallee(path) || isInCallee(path)) {
    return;
  }
  if (!isExecutedDuringInitialization(path)) {
    return;
  }
  if (!isInAssignmentContext(path) && !path.getStatementParent().isExportDefaultDeclaration()) {
    return;
  }
  annotateAsPure(path);
};
var index = () => ({
  name: 'annotate-pure-calls',
  visitor: {
    'CallExpression|NewExpression': callableExpressionVisitor
  }
});

export { index as default };