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alert / js / node_modules / @babel / traverse / lib / path / introspection.js
@Réz István Réz István on 18 Nov 2021 11 KB first commit
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.matchesPattern = matchesPattern;
exports.has = has;
exports.isStatic = isStatic;
exports.isnt = isnt;
exports.equals = equals;
exports.isNodeType = isNodeType;
exports.canHaveVariableDeclarationOrExpression = canHaveVariableDeclarationOrExpression;
exports.canSwapBetweenExpressionAndStatement = canSwapBetweenExpressionAndStatement;
exports.isCompletionRecord = isCompletionRecord;
exports.isStatementOrBlock = isStatementOrBlock;
exports.referencesImport = referencesImport;
exports.getSource = getSource;
exports.willIMaybeExecuteBefore = willIMaybeExecuteBefore;
exports._guessExecutionStatusRelativeTo = _guessExecutionStatusRelativeTo;
exports._guessExecutionStatusRelativeToDifferentFunctions = _guessExecutionStatusRelativeToDifferentFunctions;
exports.resolve = resolve;
exports._resolve = _resolve;
exports.isConstantExpression = isConstantExpression;
exports.isInStrictMode = isInStrictMode;
exports.is = void 0;

var t = require("@babel/types");

function matchesPattern(pattern, allowPartial) {
  return t.matchesPattern(this.node, pattern, allowPartial);
}

function has(key) {
  const val = this.node && this.node[key];

  if (val && Array.isArray(val)) {
    return !!val.length;
  } else {
    return !!val;
  }
}

function isStatic() {
  return this.scope.isStatic(this.node);
}

const is = has;
exports.is = is;

function isnt(key) {
  return !this.has(key);
}

function equals(key, value) {
  return this.node[key] === value;
}

function isNodeType(type) {
  return t.isType(this.type, type);
}

function canHaveVariableDeclarationOrExpression() {
  return (this.key === "init" || this.key === "left") && this.parentPath.isFor();
}

function canSwapBetweenExpressionAndStatement(replacement) {
  if (this.key !== "body" || !this.parentPath.isArrowFunctionExpression()) {
    return false;
  }

  if (this.isExpression()) {
    return t.isBlockStatement(replacement);
  } else if (this.isBlockStatement()) {
    return t.isExpression(replacement);
  }

  return false;
}

function isCompletionRecord(allowInsideFunction) {
  let path = this;
  let first = true;

  do {
    const container = path.container;

    if (path.isFunction() && !first) {
      return !!allowInsideFunction;
    }

    first = false;

    if (Array.isArray(container) && path.key !== container.length - 1) {
      return false;
    }
  } while ((path = path.parentPath) && !path.isProgram());

  return true;
}

function isStatementOrBlock() {
  if (this.parentPath.isLabeledStatement() || t.isBlockStatement(this.container)) {
    return false;
  } else {
    return t.STATEMENT_OR_BLOCK_KEYS.includes(this.key);
  }
}

function referencesImport(moduleSource, importName) {
  if (!this.isReferencedIdentifier()) {
    if ((this.isMemberExpression() || this.isOptionalMemberExpression()) && (this.node.computed ? t.isStringLiteral(this.node.property, {
      value: importName
    }) : this.node.property.name === importName)) {
      const object = this.get("object");
      return object.isReferencedIdentifier() && object.referencesImport(moduleSource, "*");
    }

    return false;
  }

  const binding = this.scope.getBinding(this.node.name);
  if (!binding || binding.kind !== "module") return false;
  const path = binding.path;
  const parent = path.parentPath;
  if (!parent.isImportDeclaration()) return false;

  if (parent.node.source.value === moduleSource) {
    if (!importName) return true;
  } else {
    return false;
  }

  if (path.isImportDefaultSpecifier() && importName === "default") {
    return true;
  }

  if (path.isImportNamespaceSpecifier() && importName === "*") {
    return true;
  }

  if (path.isImportSpecifier() && t.isIdentifier(path.node.imported, {
    name: importName
  })) {
    return true;
  }

  return false;
}

function getSource() {
  const node = this.node;

  if (node.end) {
    const code = this.hub.getCode();
    if (code) return code.slice(node.start, node.end);
  }

  return "";
}

function willIMaybeExecuteBefore(target) {
  return this._guessExecutionStatusRelativeTo(target) !== "after";
}

function getOuterFunction(path) {
  return (path.scope.getFunctionParent() || path.scope.getProgramParent()).path;
}

function isExecutionUncertain(type, key) {
  switch (type) {
    case "LogicalExpression":
      return key === "right";

    case "ConditionalExpression":
    case "IfStatement":
      return key === "consequent" || key === "alternate";

    case "WhileStatement":
    case "DoWhileStatement":
    case "ForInStatement":
    case "ForOfStatement":
      return key === "body";

    case "ForStatement":
      return key === "body" || key === "update";

    case "SwitchStatement":
      return key === "cases";

    case "TryStatement":
      return key === "handler";

    case "AssignmentPattern":
      return key === "right";

    case "OptionalMemberExpression":
      return key === "property";

    case "OptionalCallExpression":
      return key === "arguments";

    default:
      return false;
  }
}

function isExecutionUncertainInList(paths, maxIndex) {
  for (let i = 0; i < maxIndex; i++) {
    const path = paths[i];

    if (isExecutionUncertain(path.parent.type, path.parentKey)) {
      return true;
    }
  }

  return false;
}

function _guessExecutionStatusRelativeTo(target) {
  const funcParent = {
    this: getOuterFunction(this),
    target: getOuterFunction(target)
  };

  if (funcParent.target.node !== funcParent.this.node) {
    return this._guessExecutionStatusRelativeToDifferentFunctions(funcParent.target);
  }

  const paths = {
    target: target.getAncestry(),
    this: this.getAncestry()
  };
  if (paths.target.indexOf(this) >= 0) return "after";
  if (paths.this.indexOf(target) >= 0) return "before";
  let commonPath;
  const commonIndex = {
    target: 0,
    this: 0
  };

  while (!commonPath && commonIndex.this < paths.this.length) {
    const path = paths.this[commonIndex.this];
    commonIndex.target = paths.target.indexOf(path);

    if (commonIndex.target >= 0) {
      commonPath = path;
    } else {
      commonIndex.this++;
    }
  }

  if (!commonPath) {
    throw new Error("Internal Babel error - The two compared nodes" + " don't appear to belong to the same program.");
  }

  if (isExecutionUncertainInList(paths.this, commonIndex.this - 1) || isExecutionUncertainInList(paths.target, commonIndex.target - 1)) {
    return "unknown";
  }

  const divergence = {
    this: paths.this[commonIndex.this - 1],
    target: paths.target[commonIndex.target - 1]
  };

  if (divergence.target.listKey && divergence.this.listKey && divergence.target.container === divergence.this.container) {
    return divergence.target.key > divergence.this.key ? "before" : "after";
  }

  const keys = t.VISITOR_KEYS[commonPath.type];
  const keyPosition = {
    this: keys.indexOf(divergence.this.parentKey),
    target: keys.indexOf(divergence.target.parentKey)
  };
  return keyPosition.target > keyPosition.this ? "before" : "after";
}

const executionOrderCheckedNodes = new WeakSet();

function _guessExecutionStatusRelativeToDifferentFunctions(target) {
  if (!target.isFunctionDeclaration() || target.parentPath.isExportDeclaration()) {
    return "unknown";
  }

  const binding = target.scope.getBinding(target.node.id.name);
  if (!binding.references) return "before";
  const referencePaths = binding.referencePaths;
  let allStatus;

  for (const path of referencePaths) {
    const childOfFunction = !!path.find(path => path.node === target.node);
    if (childOfFunction) continue;

    if (path.key !== "callee" || !path.parentPath.isCallExpression()) {
      return "unknown";
    }

    if (executionOrderCheckedNodes.has(path.node)) continue;
    executionOrderCheckedNodes.add(path.node);

    const status = this._guessExecutionStatusRelativeTo(path);

    executionOrderCheckedNodes.delete(path.node);

    if (allStatus && allStatus !== status) {
      return "unknown";
    } else {
      allStatus = status;
    }
  }

  return allStatus;
}

function resolve(dangerous, resolved) {
  return this._resolve(dangerous, resolved) || this;
}

function _resolve(dangerous, resolved) {
  if (resolved && resolved.indexOf(this) >= 0) return;
  resolved = resolved || [];
  resolved.push(this);

  if (this.isVariableDeclarator()) {
    if (this.get("id").isIdentifier()) {
      return this.get("init").resolve(dangerous, resolved);
    } else {}
  } else if (this.isReferencedIdentifier()) {
    const binding = this.scope.getBinding(this.node.name);
    if (!binding) return;
    if (!binding.constant) return;
    if (binding.kind === "module") return;

    if (binding.path !== this) {
      const ret = binding.path.resolve(dangerous, resolved);
      if (this.find(parent => parent.node === ret.node)) return;
      return ret;
    }
  } else if (this.isTypeCastExpression()) {
    return this.get("expression").resolve(dangerous, resolved);
  } else if (dangerous && this.isMemberExpression()) {
    const targetKey = this.toComputedKey();
    if (!t.isLiteral(targetKey)) return;
    const targetName = targetKey.value;
    const target = this.get("object").resolve(dangerous, resolved);

    if (target.isObjectExpression()) {
      const props = target.get("properties");

      for (const prop of props) {
        if (!prop.isProperty()) continue;
        const key = prop.get("key");
        let match = prop.isnt("computed") && key.isIdentifier({
          name: targetName
        });
        match = match || key.isLiteral({
          value: targetName
        });
        if (match) return prop.get("value").resolve(dangerous, resolved);
      }
    } else if (target.isArrayExpression() && !isNaN(+targetName)) {
      const elems = target.get("elements");
      const elem = elems[targetName];
      if (elem) return elem.resolve(dangerous, resolved);
    }
  }
}

function isConstantExpression() {
  if (this.isIdentifier()) {
    const binding = this.scope.getBinding(this.node.name);
    if (!binding) return false;
    return binding.constant;
  }

  if (this.isLiteral()) {
    if (this.isRegExpLiteral()) {
      return false;
    }

    if (this.isTemplateLiteral()) {
      return this.get("expressions").every(expression => expression.isConstantExpression());
    }

    return true;
  }

  if (this.isUnaryExpression()) {
    if (this.node.operator !== "void") {
      return false;
    }

    return this.get("argument").isConstantExpression();
  }

  if (this.isBinaryExpression()) {
    return this.get("left").isConstantExpression() && this.get("right").isConstantExpression();
  }

  return false;
}

function isInStrictMode() {
  const start = this.isProgram() ? this : this.parentPath;
  const strictParent = start.find(path => {
    if (path.isProgram({
      sourceType: "module"
    })) return true;
    if (path.isClass()) return true;
    if (!path.isProgram() && !path.isFunction()) return false;

    if (path.isArrowFunctionExpression() && !path.get("body").isBlockStatement()) {
      return false;
    }

    const body = path.isFunction() ? path.node.body : path.node;

    for (const directive of body.directives) {
      if (directive.value.value === "use strict") {
        return true;
      }
    }
  });
  return !!strictParent;
}