@rushstack/tree-pattern - npm Package Compare versions

Comparing version 0.2.2 to 0.2.3

dist/tsdoc-metadata.json

		@@ -8,5 +8,5 @@ // This file is read by tools that parse documentation comments conforming to the TSDoc standard.
		"packageName": "@microsoft/api-extractor",
		"packageVersion": "7.18.15"
		"packageVersion": "7.19.4"
		}
		]
		}

package.json

		{
		"name": "@rushstack/tree-pattern",
		"version": "0.2.2",
		"version": "0.2.3",
		"description": "A fast, lightweight pattern matcher for tree structures such as an Abstract Syntax Tree (AST)",
		@@ -13,13 +13,16 @@ "main": "lib/index.js",
		},
		"scripts": {
		"build": "heft test --clean"
		},
		"devDependencies": {
		"@rushstack/eslint-config": "2.4.2",
		"@rushstack/heft": "0.41.6",
		"@rushstack/heft-node-rig": "1.2.25",
		"@rushstack/eslint-config": "2.5.1",
		"@rushstack/heft": "0.44.2",
		"@rushstack/heft-node-rig": "1.7.1",
		"@types/heft-jest": "1.0.1",
		"eslint": "~7.30.0",
		"typescript": "~4.4.2"
		}
		}
		"typescript": "~4.5.2"
		},
		"scripts": {
		"build": "heft build --clean",
		"_phase:build": "heft build --clean",
		"_phase:test": "heft test --no-build"
		},
		"readme": "# @rushstack/tree-pattern\n\nThis is a simple, fast pattern matcher for JavaScript tree structures. It was designed for ESLint rules and\ntransforms that match parse trees such as produced by [Esprima](https://esprima.org/). However, it can be used\nwith any JSON-like data structure.\n\n## Usage\n\nSuppose we are fixing up obsolete `Promise` calls, and we need to match an input like this:\n\n```ts\nPromise.fulfilled(123);\n```\n\nThe parsed subtree looks like this:\n```js\n{\n \"type\": \"Program\",\n \"body\": [\n {\n \"type\": \"ExpressionStatement\",\n \"expression\": { // <---- expressionNode\n \"type\": \"CallExpression\",\n \"callee\": {\n \"type\": \"MemberExpression\",\n \"object\": {\n \"type\": \"Identifier\",\n \"name\": \"Promise\"\n },\n \"property\": {\n \"type\": \"Identifier\",\n \"name\": \"fulfilled\"\n },\n \"computed\": false,\n \"optional\": false\n },\n \"arguments\": [\n {\n \"type\": \"Literal\",\n \"value\": 123,\n \"raw\": \"123\"\n }\n ],\n \"optional\": false\n }\n }\n ],\n \"sourceType\": \"module\"\n}\n```\n\nThrowing away the details that we don't care about, we can specify a pattern expression with the parts\nthat need to be present:\n```js\nconst pattern1: TreePattern = new TreePattern({\n type: 'CallExpression',\n callee: {\n type: 'MemberExpression',\n object: {\n type: 'Identifier',\n name: 'Promise'\n },\n property: {\n type: 'Identifier',\n name: 'fulfilled'\n },\n computed: false\n }\n});\n```\n\nThen when our visitor encounters an `ExpressionStatement`, we can match the `expressionNode` like this:\n```js\nif (pattern1.match(expressionNode)) {\n console.log('Success!');\n}\n```\n\n## Capturing matched subtrees\n\nSuppose we want to generalize this to match any API such as `Promise.thing(123);` or `Promise.otherThing(123);`.\nWe can use a \"tag\" to extract the matching identifier:\n\n```js\nconst pattern2: TreePattern = new TreePattern({\n type: 'CallExpression',\n callee: {\n type: 'MemberExpression',\n object: {\n type: 'Identifier',\n name: 'Promise'\n },\n property: TreePattern.tag('promiseMethod', {\n type: 'Identifier'\n }),\n computed: false\n }\n});\n```\n\nOn a successful match, the tagged `promiseMethod` subtree can be retrieved like this:\n```ts\ninterface IMyCaptures {\n // Captures the \"promiseMethod\" tag specified using TreePattern.tag()\n promiseMethod?: { name?: string }; // <--- substitute your real AST interface here\n}\n\nconst captures: IMyCaptures = {};\n\nif (pattern2.match(node, captures)) {\n // Prints: \"Matched fulfilled\"\n console.log('Matched ' + captures?.promiseMethod?.name);\n}\n```\n\n## Alternative subtrees\n\nThe `oneOf` API enables you to write patterns that match alternative subtrees.\n\n```ts\nconst pattern3: TreePattern = new TreePattern({\n animal: TreePattern.oneOf([\n { kind: 'dog', bark: 'loud' },\n { kind: 'cat', meow: 'quiet' }\n ])\n});\n\nif (pattern3.match({ animal: { kind: 'dog', bark: 'loud' } })) {\n console.log('I can match dog.');\n}\n\nif (pattern3.match({ animal: { kind: 'cat', meow: 'quiet' } })) {\n console.log('I can match cat, too.');\n}\n```\n\nFor example, maybe we want to match `Promise['fulfilled'](123);` as well as `Promise.fulfilled(123);`.\nIf the structure of the expressions is similar enough, `TreePattern.oneOf` avoids having to create two\nseparate patterns.\n\n## Links\n\n- [CHANGELOG.md](\n https://github.com/microsoft/rushstack/blob/main/libraries/tree-pattern/CHANGELOG.md) - Find\n out what's new in the latest version\n- [API Reference](https://rushstack.io/pages/api/tree-pattern/)\n\n`@rushstack/tree-pattern` is part of the [Rush Stack](https://rushstack.io/) family of projects.\n"
		}

README.md

		@@ -144,3 +144,3 @@ # @rushstack/tree-pattern
		- [CHANGELOG.md](
		https://github.com/microsoft/rushstack/blob/master/libraries/tree-pattern/CHANGELOG.md) - Find
		https://github.com/microsoft/rushstack/blob/main/libraries/tree-pattern/CHANGELOG.md) - Find
		out what's new in the latest version
		@@ -147,0 +147,0 @@ - [API Reference](https://rushstack.io/pages/api/tree-pattern/)

CHANGELOG.json

CHANGELOG.md

lib/index.js.map

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lib/TreePattern.js.map

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lib/TreePattern.test.js.map

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@rushstack/tree-pattern - npm Package Compare versions

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