How to use the isVariableDeclaration function from @babel/types
Find comprehensive JavaScript @babel/types.isVariableDeclaration code examples handpicked from public code repositorys.
@babel/types.isVariableDeclaration is a function provided by Babel that checks whether a given object represents a variable declaration.
150 151 152 153 154 155 156 157 158 159Program: { exit: function (path) { var {body} = path.node; var node = body.find(node => ( t.isVariableDeclaration(node) && (node = node.declarations[0]) && t.isIdentifier(node.id) && node.id.name === 'requireJSX' ));
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GitHub: artemave/vjs
204 205 206 207 208 209 210 211 212 213traverse(ast, { Declaration({node}) { const {loc} = node if (t.isFunctionDeclaration(node) || t.isVariableDeclaration(node) || t.isClassDeclaration(node)) { let name if (t.isVariableDeclaration(node)) { name = node.declarations[0].id.name
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How does @babel/types.isVariableDeclaration work?
@babel/types.isVariableDeclaration works by examining a given object and determining whether it represents a variable declaration.
In JavaScript, a variable declaration is a statement that declares a new variable using the var, let, or const keywords. A variable declaration can declare multiple variables at once, separated by commas.
To check whether a given object represents a variable declaration, @babel/types.isVariableDeclaration checks whether the object has a type property that equals VariableDeclaration, which is a string that represents a variable declaration in the Babel AST.
If the object is determined to represent a variable declaration, then @babel/types.isVariableDeclaration returns true. Otherwise, it returns false.
By using @babel/types.isVariableDeclaration, Babel plugin developers can programmatically determine whether a given object represents a variable declaration in the code they are processing, allowing them to perform operations on variable declarations with confidence.
90 91 92 93 94 95 96 97 98 99} path.traverse({ ThisExpression (thisPath) { const parentNode = thisPath.parentPath.parentPath.parent; const isValid = t.isExpressionStatement(parentNode) || t.isVariableDeclaration(parentNode) || t.isBlockStatement(parentNode) || t.isJSXElement(parentNode) || t.isCallExpression(parentNode) || (t.isJSXAttribute(parentNode) && !parentNode.name.name.startsWith('on'));
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162 163 164 165 166 167 168 169 170 171if(t.isExpressionStatement(path.parentPath.parent)){ candidates.unshift(path.parentPath.parent); } } if(t.isVariableDeclarator(path.parent) && t.isVariableDeclaration(path.parentPath.parent)){ candidates.unshift(path.parentPath.parent); } let annotateEverything = getAnnotations(candidates);
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Ai Example
1 2 3 4 5 6 7 8 9 10 11 12const { parse } = require("@babel/parser"); const { isVariableDeclaration } = require("@babel/types"); const code = 'const x = 42, y = "hello";'; const ast = parse(code); ast.program.body.forEach((node) => { if (isVariableDeclaration(node)) { console.log("Found a variable declaration!"); console.log(node); } });
In this example, we're using @babel/types.isVariableDeclaration to check whether each node in an Abstract Syntax Tree (AST) represents a variable declaration. We first define some code that contains a variable declaration that declares two variables, x and y, using the const keyword. We then use @babel/parser to parse this code into an AST. We then iterate over each node in the AST's program.body array, checking whether each node represents a variable declaration using @babel/types.isVariableDeclaration. If a node represents a variable declaration, we log a message to the console along with the details of the node. When we run this code, it will output the following message to the console: bash Copy code
116 117 118 119 120 121 122 123 124 125FunctionDeclaration(path) { const checkFunction = function (p) { const name = p.node.id.name; const body = p.node.body.body; return body.length === 3 && types.isVariableDeclaration(body[0]) && body[0].declarations.length === 1 && (types.isArrayExpression(body[0].declarations[0].init) || types.isCallExpression(body[0].declarations[0].init)) && types.isExpressionStatement(body[1]) && types.isAssignmentExpression(body[1].expression) && body[1].expression.left.name === name && types.isReturnStatement(body[2]); } if (!checkFunction(path)) {
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437 438 439 440 441 442 443 444 445 446}); if (t.isFile(ast) && t.isProgram(ast.program) && ast.program.body.length === 1) { const exported = ast.program.body[0]; if (t.isExportNamedDeclaration(exported) && t.isVariableDeclaration(exported.declaration) && exported.declaration.declarations.length === 1) { const declaration = exported.declaration.declarations[0]; if (t.isVariableDeclarator(declaration) && t.isIdentifier(declaration.id)) { const {
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517 518 519 520 521 522 523 524 525 526if (typeExp === "DECLARE" && types.isFunctionDeclaration(path.node)) { childToPut = types.callExpression(types.identifier(path.node.id.name), initAnnotationParser(immidateTopComment.value)); } if (typeExp === "DECLARE" && types.isVariableDeclaration(path.node) && (types.isArrowFunctionExpression(path.node.declarations[0].init) || types.isFunctionExpression(path.node.declarations[0].init))) { // console.log("variable declarator", path.node); // if ( // types.isArrowFunctionExpression(path.node.declarations[0].init) || // types.isFunctionExpression(path.node.declarations[0].init)
001GitHub: arthuredelstein/hakk
226 227 228 229 230 231 232 233 234 235 236 237 238const getEnclosingProperty = path => path.findParent((path) => path.isProperty()); const isTopLevelDeclaredObject = (path) => types.isVariableDeclarator(path.parentPath) && types.isVariableDeclaration(path.parentPath.parentPath) && types.isProgram(path.parentPath.parentPath.parentPath); const handleCallExpressionEnter = (path) => { if (path.node.callee.type !== 'MemberExpression' ||
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@babel/types.identifier is the most popular function in @babel/types (20936 examples)