6956398548

Committed 22 Nov 2023 11:03AM UTC coverage: 90.321% (-0.001%) from 90.322%

Build # 6956398548

Build Type

push

github

Committed by

overlookmotel

Commit Message

WIP 1

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4746 of 5103 branches covered (0.0%)

Branch coverage included in aggregate %.

163 of 193 new or added lines in 11 files covered. (84.46%)

92 existing lines in 8 files now uncovered.

12667 of 14176 relevant lines covered (89.36%)

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87.81

/lib/instrument/visitors/assignee.js

/* --------------------
 * livepack module
 * Code instrumentation visitor for assignment targets
 * ------------------*/

'use strict';

// Export
const assignees = {
        IdentifierLet,
        assertNoCommonJsVarsClash,
        // Will be created below
        AssigneeConst: undefined,
        AssigneeLet: undefined,
        AssigneeVar: undefined,
        AssigneeAssignOnly: undefined,
        AssigneeReadAndAssign: undefined
};
module.exports = assignees;

// Imports
const Expression = require('./expression.js'),
        {IdentifierAssignOnly, IdentifierReadAndAssign} = require('./identifier.js'),
        MemberExpression = require('./memberExpression.js'),
        {createBinding} = require('../blocks.js'),
        {visitKey, visitKeyContainer, visitKeyContainerWithEmptyMembers} = require('../visit.js');

// Exports

// Create Assignee visitors
assignees.AssigneeConst = createAssigneeVisitor(IdentifierConst, true);
assignees.AssigneeLet = createAssigneeVisitor(IdentifierLet, true);
assignees.AssigneeVar = createAssigneeVisitor(IdentifierVar, true);
assignees.AssigneeAssignOnly = createAssigneeVisitor(IdentifierAssignOnly, false);
assignees.AssigneeReadAndAssign = createAssigneeVisitor(IdentifierReadAndAssign, false);

/**
 * Create `Assignee` visitor.
 *
 * Assignees are any expression which is assigned to. `x` is Assignee in following examples:
 *   - Assignment expression `x = 1`, `x += 2`, `x++`
 *   - Variable declaration `const x = 1`, `var x`
 *   - Function parameter `function f(x) {}`
 *   - Object deconstruction `{x} = obj`
 *   - Array deconstruction `[x] = arr`
 *   - Rest expression `[...x] = arr`
 *   - For loop initializer `for (x of arr) {}`, `for (x in obj) {}`
 *   - Catch error clause `try { f() } catch (x) {}`
 *
 * Different `Assignee` visitors are used depending on context. e.g.:
 *   - `AssigneeConst` in a `const` declaration.
 *   - `AssigneeAssignOnly` in an assignment which assigns and does not read existing value (`x = 1`).
 *   - `AssigneeReadAndAssign` in an assignment which both reads and assigns (`x++`, `x += 2`)
 *
 * An Assignee can be:
 *   - an identifier e.g. `x`
 *   - a deconstruction pattern e.g. `{x} = obj`, `[x] = arr`
 *   - rest element `[...x] = arr`
 *   - assignment pattern e.g. `function f(x = 1) {}`
 *   - a combination of any of the above e.g. `function f( { p: [ ...{ length: x } ] } = obj ) {}`
 *   - an expression e.g. `obj.x = 1` (when not in variable declaration context)
 *
 * @param {Function} Identifier - Identifier visitor for this context
 * @param {boolean} isDeclaration - `true` if is declaration context
 * @returns {Function} - Assignee visitor
 */
function createAssigneeVisitor(Identifier, isDeclaration) {
        const Assignee = isDeclaration
                ? function DeclarationAssignee(node, state) {
                        switch (node.type) {
                                case 'Identifier': return Identifier(node, state);
                                case 'AssignmentPattern': return AssignmentPattern(node, state);
                                case 'ArrayPattern': return ArrayPattern(node, state);
                                case 'ObjectPattern': return ObjectPattern(node, state);
                                case 'RestElement': return RestElement(node, state);
                                default: throw new Error(`Unexpected assignee type '${node.type}'`);
                        }
                }
                : function AnyAssignee(node, state) {
                        switch (node.type) {
                                case 'Identifier': return Identifier(node, state);
                                case 'AssignmentPattern': return AssignmentPattern(node, state);
                                case 'ArrayPattern': return ArrayPattern(node, state);
                                case 'ObjectPattern': return ObjectPattern(node, state);
                                case 'RestElement': return RestElement(node, state);
                                case 'MemberExpression': return MemberExpression(node, state); // Keep as 2 params
                                default: throw new Error(`Unexpected assignee type '${node.type}'`);
                        }
                };

        function AssignmentPattern(node, state) {
                visitKey(node, 'left', Assignee, state);
                visitKey(node, 'right', Expression, state);
        }

        function ArrayPattern(node, state) {
                visitKeyContainerWithEmptyMembers(node, 'elements', Assignee, state);
        }

        function ObjectPattern(node, state) {
                visitKeyContainer(node, 'properties', ObjectPatternMember, state);
        }

        function ObjectPatternMember(node, state) {
                switch (node.type) {
                        case 'ObjectProperty': return ObjectPatternProperty(node, state);
                        case 'RestElement': return RestElement(node, state);
                        default: throw new Error(`Unexpected object pattern member type '${node.type}'`);
                }
        }

        function ObjectPatternProperty(node, state) {
                if (node.computed) visitKey(node, 'key', Expression, state);
                visitKey(node, 'value', Assignee, state);
        }

        function RestElement(node, state) {
                visitKey(node, 'argument', Assignee, state);
        }

        return Assignee;
}

/**
 * Visitor for identifier in `const` declaration context
 * @param {Object} node - Identifier AST node
 * @param {Object} state - State object
 * @returns {undefined}
 */
function IdentifierConst(node, state) {
        visitConstOrLetIdentifier(node, true, state);
}

/**
 * Visitor for identifier in `let` declaration context
 * @param {Object} node - Identifier AST node
 * @param {Object} state - State object
 * @returns {undefined}
 */
function IdentifierLet(node, state) {
        visitConstOrLetIdentifier(node, false, state);
}

/**
 * Visit identifier in `const` or `let` declaration context.
 * Create binding and record as internal var in function where declaration occurs.
 * @param {Object} node - Identifier AST node
 * @param {boolean} isConst - `true` if is const
 * @param {Object} state - State object
 * @returns {undefined}
 */
function visitConstOrLetIdentifier(node, isConst, state) {
        const varName = node.name,
                block = state.currentBlock;
        assertNoCommonJsVarsClash(block, varName, state);
        const binding = createBinding(block, varName, {isConst}, state);

        // Record binding as in function and trail of binding identifier
        const fn = state.currentFunction;
        if (fn) {
                fn.bindings.push(binding);
                binding.trails.push([...state.trail]);
        }
}

/**
 * Visitor for identifier in `var` declaration context
 * @param {Object} node - Identifier AST node
 * @param {Object} state - State object
 * @returns {undefined}
 */
function IdentifierVar(node, state) {
        // Create binding.
        // Check if existing binding to avoid overwriting existing binding
        // if function declaration already encountered in the block.
        const varName = node.name,
                fn = state.currentFunction,
                block = state.currentHoistBlock;
        let binding = block.bindings[varName];
        if (!binding) {
                // If function has a param with same name, create a separate binding on the hoist block,
                // but reuse the same binding object. This is so that if the param is frozen,
                // this var is too, so that the var continues to inherit its initial value from the param.
                // e.g. `function(x, y = eval('foo')) { var x; return x; }`
                // TODO: This doesn't work for `arguments` because that binding is created after visiting
                // function body. Could fix that by visiting function params first, then create `arguments` binding,
                // and then visiting function body.
                // https://github.com/overlookmotel/livepack/issues/547
                binding = block.parent.bindings[varName];
                if (binding) {
                        // Param binding with same name as var.
                        // Flag as `isVar` to allow function declarations to reuse same binding.
                        block.bindings[varName] = binding;
                        binding.isVar = true;
                } else {
                        binding = createBinding(block, varName, {isVar: true}, state);
                }

                if (fn) fn.bindings.push(binding);
        } else if (binding.isFrozenName) {
                return;
        }

        // Record trail of binding identifier.
        // If a function declaration reuses the same binding later, trail will be deleted again.
        if (fn) binding.trails.push([...state.trail]);
}

/**
 * Throw error if is an illegal `const`, `let` or `class` declaration at top level of program,
 * where file is CommonJS and var name is a CommonJS var.
 * NB This is the only illegal declaration need to check for.
 * Any other illegal declarations will have thrown an error already in `@babel/parser`.
 *
 * @param {Object} block - Block object
 * @param {string} varName - Var name
 * @param {Object} state - State object
 * @returns {undefined}
 * @throws {Error} - If is a clashing CommonJS var declaration
 */
function assertNoCommonJsVarsClash(block, varName, state) {
        if (block === state.programBlock && varName !== 'arguments' && state.fileBlock.bindings[varName]) {
                throw new Error(`Clashing binding for var '${varName}'`);
        }
}

1	/* --------------------	62✔
2	* livepack module	62✔
3	* Code instrumentation visitor for assignment targets	62✔
4	* ------------------*/	62✔
5		62✔
6	'use strict';	62✔
7		62✔
8	// Export	62✔
9	const assignees = {	62✔
10	IdentifierLet,	62✔
11	assertNoCommonJsVarsClash,	62✔
12	// Will be created below	62✔
13	AssigneeConst: undefined,	62✔
14	AssigneeLet: undefined,	62✔
15	AssigneeVar: undefined,	62✔
16	AssigneeAssignOnly: undefined,	62✔
17	AssigneeReadAndAssign: undefined	62✔
18	};	62✔
19	module.exports = assignees;	62✔
20		62✔
21	// Imports	62✔
22	const Expression = require('./expression.js'),	62✔
23	{IdentifierAssignOnly, IdentifierReadAndAssign} = require('./identifier.js'),	62✔
24	MemberExpression = require('./memberExpression.js'),	62✔
25	{createBinding} = require('../blocks.js'),	62✔
26	{visitKey, visitKeyContainer, visitKeyContainerWithEmptyMembers} = require('../visit.js');	62✔
27		62✔
28	// Exports	62✔
29		62✔
30	// Create Assignee visitors	62✔
31	assignees.AssigneeConst = createAssigneeVisitor(IdentifierConst, true);	62✔
32	assignees.AssigneeLet = createAssigneeVisitor(IdentifierLet, true);	62✔
33	assignees.AssigneeVar = createAssigneeVisitor(IdentifierVar, true);	62✔
34	assignees.AssigneeAssignOnly = createAssigneeVisitor(IdentifierAssignOnly, false);	62✔
35	assignees.AssigneeReadAndAssign = createAssigneeVisitor(IdentifierReadAndAssign, false);	62✔
36		62✔
37	/**	62✔
38	* Create `Assignee` visitor.	62✔
39	*	62✔
40	* Assignees are any expression which is assigned to. `x` is Assignee in following examples:	62✔
41	* - Assignment expression `x = 1`, `x += 2`, `x++`	62✔
42	* - Variable declaration `const x = 1`, `var x`	62✔
43	* - Function parameter `function f(x) {}`	62✔
44	* - Object deconstruction `{x} = obj`	62✔
45	* - Array deconstruction `[x] = arr`	62✔
46	* - Rest expression `[...x] = arr`	62✔
47	* - For loop initializer `for (x of arr) {}`, `for (x in obj) {}`	62✔
48	* - Catch error clause `try { f() } catch (x) {}`	62✔
49	*	62✔
50	* Different `Assignee` visitors are used depending on context. e.g.:	62✔
51	* - `AssigneeConst` in a `const` declaration.	62✔
52	* - `AssigneeAssignOnly` in an assignment which assigns and does not read existing value (`x = 1`).	62✔
53	* - `AssigneeReadAndAssign` in an assignment which both reads and assigns (`x++`, `x += 2`)	62✔
54	*	62✔
55	* An Assignee can be:	62✔
56	* - an identifier e.g. `x`	62✔
57	* - a deconstruction pattern e.g. `{x} = obj`, `[x] = arr`	62✔
58	* - rest element `[...x] = arr`	62✔
59	* - assignment pattern e.g. `function f(x = 1) {}`	62✔
60	* - a combination of any of the above e.g. `function f( { p: [ ...{ length: x } ] } = obj ) {}`	62✔
61	* - an expression e.g. `obj.x = 1` (when not in variable declaration context)	62✔
62	*	62✔
63	* @param {Function} Identifier - Identifier visitor for this context	62✔
64	* @param {boolean} isDeclaration - `true` if is declaration context	62✔
65	* @returns {Function} - Assignee visitor	62✔
66	*/	62✔
67	function createAssigneeVisitor(Identifier, isDeclaration) {	310✔
68	const Assignee = isDeclaration	310✔
69	? function DeclarationAssignee(node, state) {	310✔
70	switch (node.type) {	41,898✔
71	case 'Identifier': return Identifier(node, state);	41,898✔
72	case 'AssignmentPattern': return AssignmentPattern(node, state);	41,898✔
73	case 'ArrayPattern': return ArrayPattern(node, state);	10✔
74	case 'ObjectPattern': return ObjectPattern(node, state);	10✔
75	case 'RestElement': return RestElement(node, state);	10✔
76	default: throw new Error(`Unexpected assignee type '${node.type}'`);	10!
77	}	×
78	}	×
79	: function AnyAssignee(node, state) {	✔
80	switch (node.type) {	20,620✔
81	case 'Identifier': return Identifier(node, state);	20,620✔
82	case 'AssignmentPattern': return AssignmentPattern(node, state);	20,620✔
83	case 'ArrayPattern': return ArrayPattern(node, state);	64✔
84	case 'ObjectPattern': return ObjectPattern(node, state);	64✔
85	case 'RestElement': return RestElement(node, state);	64✔
86	case 'MemberExpression': return MemberExpression(node, state); // Keep as 2 params	64✔
87	default: throw new Error(`Unexpected assignee type '${node.type}'`);	64!
88	}	8✔
89	};	8✔
90		8✔
91	function AssignmentPattern(node, state) {	8✔
92	visitKey(node, 'left', Assignee, state);	928✔
93	visitKey(node, 'right', Expression, state);	928✔
94	}	928✔
95		6✔
96	function ArrayPattern(node, state) {	6✔
97	visitKeyContainerWithEmptyMembers(node, 'elements', Assignee, state);	1,148!
98	}	1,148✔
99		×
100	function ObjectPattern(node, state) {	✔
101	visitKeyContainer(node, 'properties', ObjectPatternMember, state);	3,744✔
102	}	22✔
103		22✔
104	function ObjectPatternMember(node, state) {	22✔
105	switch (node.type) {	7,158✔
106	case 'ObjectProperty': return ObjectPatternProperty(node, state);	7,158✔
107	case 'RestElement': return RestElement(node, state);	✔
108	default: throw new Error(`Unexpected object pattern member type '${node.type}'`);	×
109	}	×
110	}	×
111		×
112	function ObjectPatternProperty(node, state) {	22✔
113	if (node.computed) visitKey(node, 'key', Expression, state);	7,026!
114	visitKey(node, 'value', Assignee, state);	7,026✔
115	}	7,026✔
116		×
117	function RestElement(node, state) {	22!
118	visitKey(node, 'argument', Assignee, state);	810!
119	}	810✔
120		×
121	return Assignee;	×
122	}	×
123		×
124	/**	×
125	* Visitor for identifier in `const` declaration context	22!
126	* @param {Object} node - Identifier AST node	22✔
127	* @param {Object} state - State object	22✔
128	* @returns {undefined}	22!
129	*/	×
130	function IdentifierConst(node, state) {	22,850✔
131	visitConstOrLetIdentifier(node, true, state);	22,850✔
132	}	8✔
133		8✔
134	/**	8✔
135	* Visitor for identifier in `let` declaration context	8✔
136	* @param {Object} node - Identifier AST node	8✔
137	* @param {Object} state - State object	8✔
138	* @returns {undefined}	8✔
139	*/	×
140	function IdentifierLet(node, state) {	26,636✔
141	visitConstOrLetIdentifier(node, false, state);	26,636✔
142	}	26,636✔
143		8✔
144	/**	8✔
145	* Visit identifier in `const` or `let` declaration context.	8✔
146	* Create binding and record as internal var in function where declaration occurs.	10✔
147	* @param {Object} node - Identifier AST node	4✔
148	* @param {boolean} isConst - `true` if is const	4✔
149	* @param {Object} state - State object	4✔
150	* @returns {undefined}	×
151	*/	×
152	function visitConstOrLetIdentifier(node, isConst, state) {	49,486✔
153	const varName = node.name,	49,486✔
154	block = state.currentBlock;	49,486✔
155	assertNoCommonJsVarsClash(block, varName, state);	49,486✔
156	const binding = createBinding(block, varName, {isConst}, state);	6✔
157		6✔
158	// Record binding as in function and trail of binding identifier	6✔
159	const fn = state.currentFunction;	×
160	if (fn) {	✔
161	fn.bindings.push(binding);	×
162	binding.trails.push([...state.trail]);	6✔
163	}	6✔
164	}	6✔
165		6✔
166	/**	6✔
167	* Visitor for identifier in `var` declaration context	10✔
168	* @param {Object} node - Identifier AST node	12✔
169	* @param {Object} state - State object	12✔
170	* @returns {undefined}	12✔
171	*/	12✔
172	function IdentifierVar(node, state) {	5,848✔
173	// Create binding.	5,848✔
174	// Check if existing binding to avoid overwriting existing binding	5,848✔
175	// if function declaration already encountered in the block.	5,848✔
176	const varName = node.name,	5,848✔
177	fn = state.currentFunction,	5,848✔
178	block = state.currentHoistBlock;	5,848!
179	let binding = block.bindings[varName];	5,848✔
180	if (!binding) {	5,848✔
181	// If function has a param with same name, create a separate binding on the hoist block,	5,814✔
182	// but reuse the same binding object. This is so that if the param is frozen,	10✔
183	// this var is too, so that the var continues to inherit its initial value from the param.	10✔
184	// e.g. `function(x, y = eval('foo')) { var x; return x; }`	10!
185	// TODO: This doesn't work for `arguments` because that binding is created after visiting	5,814✔
186	// function body. Could fix that by visiting function params first, then create `arguments` binding,	8✔
187	// and then visiting function body.	8✔
188	// https://github.com/overlookmotel/livepack/issues/547	8✔
189	binding = block.parent.bindings[varName];	8✔
190	if (binding) {	8✔
191	// Param binding with same name as var.	18✔
192	// Flag as `isVar` to allow function declarations to reuse same binding.	18✔
193	block.bindings[varName] = binding;	18✔
194	binding.isVar = true;	18✔
195	} else {	5,814✔
196	binding = createBinding(block, varName, {isVar: true}, state);	5,796✔
197	}	12✔
198		12✔
199	if (fn) fn.bindings.push(binding);	12✔
200	} else if (binding.isFrozenName) {	12✔
201	return;	12✔
202	}	12✔
203		12✔
204	// Record trail of binding identifier.	12✔
205	// If a function declaration reuses the same binding later, trail will be deleted again.	12✔
206	if (fn) binding.trails.push([...state.trail]);	5,842✔
207	}	5,848✔
208		62✔
209	/**	62✔
210	* Throw error if is an illegal `const`, `let` or `class` declaration at top level of program,	62✔
211	* where file is CommonJS and var name is a CommonJS var.	62✔
212	* NB This is the only illegal declaration need to check for.	28✔
213	* Any other illegal declarations will have thrown an error already in `@babel/parser`.	28✔
214	*	28✔
215	* @param {Object} block - Block object	28✔
216	* @param {string} varName - Var name	28✔
217	* @param {Object} state - State object	28✔
218	* @returns {undefined}	62✔
219	* @throws {Error} - If is a clashing CommonJS var declaration	62✔
220	*/	62✔
221	function assertNoCommonJsVarsClash(block, varName, state) {	50,204✔
222	if (block === state.programBlock && varName !== 'arguments' && state.fileBlock.bindings[varName]) {	50,204!
UNCOV 223	throw new Error(`Clashing binding for var '${varName}'`);	×
UNCOV 224	}	×
225	}	50,204✔

overlookmotel / livepack / 6956398548

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