luhn-generator
Version:
A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm
269 lines (217 loc) • 6.96 kB
JavaScript
"use strict";
const CountedSet = require("./counted-set");
const isLabelIdentifier = require("./is-label-identifier");
const newIssueUrl = "https://github.com/babel/minify/issues/new";
/**
* ScopeTracker
* references: Map<Scope, CountedSet<String> >
* bindings: Map<Scope, Map<String, Binding> >
*/
module.exports = class ScopeTracker {
constructor() {
this.references = new Map();
this.bindings = new Map();
}
/**
* Register a new Scope and initiliaze it with empty sets
* @param {Scope} scope
*/
addScope(scope) {
if (!this.references.has(scope)) {
this.references.set(scope, new CountedSet());
}
if (!this.bindings.has(scope)) {
this.bindings.set(scope, new Map());
}
}
/**
* Add reference to all Scopes between and including the ReferencedScope
* and Binding's Scope
* @param {Scope} scope
* @param {Binding} binding
* @param {String} name
*/
addReference(scope, binding, name) {
let parent = scope;
do {
this.references.get(parent).add(name);
if (!binding) {
throw new Error(`Binding Not Found for ${name} during scopeTracker.addRefernce. ` + `Please report at ${newIssueUrl}`);
}
if (binding.scope === parent) break;
} while (parent = parent.parent);
}
/**
* has a Reference in the given {Scope} or a child Scope
*
* Refer {addReference} to know why the following call will be valid
* for detecting references in child Scopes
*
* @param {Scope} scope
* @param {String} name
*/
hasReference(scope, name) {
return this.references.get(scope).has(name);
}
/**
* Update reference count in all scopes between and including the
* Referenced Scope and the Binding's Scope
*
* @param {Scope} scope
* @param {Binding} binding
* @param {String} oldName
* @param {String} newName
*/
updateReference(scope, binding, oldName, newName) {
let parent = scope;
do {
const ref = this.references.get(parent);
ref.delete(oldName);
ref.add(newName);
if (!binding) {
// Something went wrong - panic
throw new Error("Binding Not Found during scopeTracker.updateRefernce " + `while updating "${oldName}" to "${newName}". ` + `Please report at ${newIssueUrl}`);
}
if (binding.scope === parent) break;
} while (parent = parent.parent);
}
/**
* has either a Binding or a Reference
* @param {Scope} scope
* @param {Binding} binding
* @param {String} name
*/
hasBindingOrReference(scope, binding, name) {
return this.hasReference(scope, name) || this.hasBinding(scope, name);
}
/**
* For a Binding visit all places where the Binding is used and detect
* if the newName {next} can be used in all these places
*
* 1. binding's own scope
* 2. constant violations' scopes
* 3. referencePaths' scopes
*
* @param {Binding} binding
* @param {String} next
*/
canUseInReferencedScopes(binding, next) {
const tracker = this;
if (tracker.hasBindingOrReference(binding.scope, binding, next)) {
return false;
} // Safari raises a syntax error for a `let` or `const` declaration in a
// `for` loop initialization that shadows a parent function's parameter.
// https://github.com/babel/minify/issues/559
// https://bugs.webkit.org/show_bug.cgi?id=171041
// https://trac.webkit.org/changeset/217200/webkit/trunk/Source
const maybeDecl = binding.path.parentPath;
const isBlockScoped = maybeDecl.isVariableDeclaration({
kind: "let"
}) || maybeDecl.isVariableDeclaration({
kind: "const"
});
if (isBlockScoped) {
const maybeFor = maybeDecl.parentPath;
const isForLoopBinding = maybeFor.isForStatement({
init: maybeDecl.node
}) || maybeFor.isForXStatement({
left: maybeDecl.node
});
if (isForLoopBinding) {
const fnParent = getFunctionParent(maybeFor);
if (fnParent.isFunction({
body: maybeFor.parent
})) {
const parentFunctionBinding = this.bindings.get(fnParent.scope).get(next);
if (parentFunctionBinding) {
const parentFunctionHasParamBinding = parentFunctionBinding.kind === "param";
if (parentFunctionHasParamBinding) {
return false;
}
}
}
}
}
for (let i = 0; i < binding.constantViolations.length; i++) {
const violation = binding.constantViolations[i];
if (tracker.hasBindingOrReference(violation.scope, binding, next)) {
return false;
}
}
for (let i = 0; i < binding.referencePaths.length; i++) {
const ref = binding.referencePaths[i];
if (!ref.isIdentifier()) {
let canUse = true;
ref.traverse({
ReferencedIdentifier(path) {
if (path.node.name !== next) return;
if (tracker.hasBindingOrReference(path.scope, binding, next)) {
canUse = false;
}
}
});
if (!canUse) {
return canUse;
}
} else if (!isLabelIdentifier(ref)) {
if (tracker.hasBindingOrReference(ref.scope, binding, next)) {
return false;
}
}
}
return true;
}
/**
* Add a binding to Tracker in binding's own Scope
* @param {Binding} binding
*/
addBinding(binding) {
if (!binding) {
return;
}
const bindings = this.bindings.get(binding.scope);
const existingBinding = bindings.get(binding.identifier.name);
if (existingBinding && existingBinding !== binding) {
throw new Error(`scopeTracker.addBinding: ` + `Binding "${existingBinding.identifier.name}" already exists. ` + `Trying to add "${binding.identifier.name}" again.`);
}
bindings.set(binding.identifier.name, binding);
}
/**
* Moves Binding from it's own Scope to {@param toScope}
*
* required for fixup-var-scope
*
* @param {Binding} binding
* @param {Scope} toScope
*/
moveBinding(binding, toScope) {
this.bindings.get(binding.scope).delete(binding.identifier.name);
this.bindings.get(toScope).set(binding.identifier.name, binding);
}
/**
* has a Binding in the current {Scope}
* @param {Scope} scope
* @param {String} name
*/
hasBinding(scope, name) {
return this.bindings.get(scope).has(name);
}
/**
* Update the ScopeTracker on rename
* @param {Scope} scope
* @param {String} oldName
* @param {String} newName
*/
renameBinding(scope, oldName, newName) {
const bindings = this.bindings.get(scope);
bindings.set(newName, bindings.get(oldName));
bindings.delete(oldName);
}
};
/**
* Babel-7 returns null if there is no function parent
* and uses getProgramParent to get Program
*/
function getFunctionParent(path) {
return (path.scope.getFunctionParent() || path.scope.getProgramParent()).path;
}