Subsume json (#7985)

* Add Subsume JSON transform

https://github.com/tc39/proposal-json-superset is at stage 3.

This allows U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR to appear unescaped inside strings and directives.

* Move to Stage 3

* Break diretive parsing

* Update README

* Handle multi-escape sequences

* Remove babylon files after rename

packages/babel-plugin-proposal-json-strings/.npmignore

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+src
+test
+*.log

packages/babel-plugin-proposal-json-strings/README.md

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+# @babel/plugin-syntax-json-strings
+
+Allow parsing of the U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR in JS strings
+
+## Examples
+
+**In**
+
+```js
+const ex = "before
after";
+//                ^ There's a U+2028 char between 'before' and 'after'
+```
+
+**Out**
+
+```js
+const ex = "before\u2028after";
+//                ^ There's a U+2028 char between 'before' and 'after'
+```
+
+## Installation
+
+```sh
+npm install --save-dev @babel/plugin-proposal-json-strings
+```
+
+## Usage
+
+### Via `.babelrc` (Recommended)
+
+**.babelrc**
+
+```json
+{
+  "plugins": ["@babel/plugin-proposal-json-strings"]
+}
+```
+
+### Via CLI
+
+```sh
+babel --plugins @babel/plugin-proposal-json-strings script.js
+```
+
+### Via Node API
+
+```javascript
+require("@babel/core").transform("code", {
+  plugins: ["@babel/plugin-proposal-json-strings"]
+});
+```
+
+## References
+- [Proposal: Optional Catch Binding for ECMAScript](https://github.com/babel/proposals/issues/7)

packages/babel-plugin-proposal-json-strings/package.json

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+{
+  "name": "@babel/plugin-proposal-json-strings",
+  "version": "7.0.0-beta.47",
+  "description": "Escape U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR in JS strings",
+  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-json-strings",
+  "license": "MIT",
+  "main": "lib/index.js",
+  "keywords": [
+    "babel-plugin"
+  ],
+  "dependencies": {
+    "@babel/helper-plugin-utils": "7.0.0-beta.47",
+    "@babel/plugin-syntax-json-strings": "7.0.0-beta.47"
+  },
+  "peerDependencies": {
+    "@babel/core": "7.0.0-beta.47"
+  },
+  "devDependencies": {
+    "@babel/core": "7.0.0-beta.47",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.47"
+  }
+}

packages/babel-plugin-proposal-json-strings/src/index.js

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+import { declare } from "@babel/helper-plugin-utils";
+import syntaxJsonStrings from "@babel/plugin-syntax-json-strings";
+
+export default declare(api => {
+  api.assertVersion(7);
+  const regex = /(\\*)([\u2028\u2029])/g;
+  function replace(match, escapes, separator) {
+    // If there's an odd number, that means the separator itself was escaped.
+    // "\X" escapes X.
+    // "\\X" escapes the backslash, so X is unescaped.
+    const isEscaped = escapes.length % 2 === 1;
+    if (isEscaped) return match;
+
+    return `${escapes}\\u${separator.charCodeAt(0).toString(16)}`;
+  }
+
+  return {
+    inherits: syntaxJsonStrings,
+
+    visitor: {
+      "DirectiveLiteral|StringLiteral"({ node }) {
+        const { extra } = node;
+        if (!extra || !extra.raw) return;
+
+        extra.raw = extra.raw.replace(regex, replace);
+      },
+    },
+  };
+});

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/directive-line-separator/exec.js

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+"before
after";
+//     ^ That's a U+2028 LINE SEPARATOR UTF-16 char (between 'before' and 'after')
+"
"; // Just a U+2028 LINE SEPARATOR
+"\
"; // Escaped U+2028 LINE SEPARATOR
+"\u2028"; // Escaped U+2028 LINE SEPARATOR

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/directive-line-separator/input.js

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+"before
after";
+//     ^ That's a U+2028 LINE SEPARATOR UTF-16 char (between 'before' and 'after')
+"
"; // Just a U+2028 LINE SEPARATOR
+"\
"; // Escaped U+2028 LINE SEPARATOR
+"\u2028"; // Escaped U+2028 LINE SEPARATOR

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/directive-line-separator/output.js

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+"before\u2028after"; //     ^ That's a U+2028 LINE SEPARATOR UTF-16 char (between 'before' and 'after')
+
+"\u2028"; // Just a U+2028 LINE SEPARATOR
+
+"\
"; // Escaped U+2028 LINE SEPARATOR
+
+"\u2028"; // Escaped U+2028 LINE SEPARATOR

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/directive-paragraph-separator/exec.js

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+"before
after";
+//     ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char (between 'before' and 'after')
+"
"; // Just a U+2029 PARAGRAPH SEPARATOR
+"\
"; // Escaped U+2029 PARAGRAPH SEPARATOR
+"\u2029"; // Escaped U+2029 PARAGRAPH SEPARATOR

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/directive-paragraph-separator/input.js

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+"before
after";
+//     ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char (between 'before' and 'after')
+"
"; // Just a U+2029 PARAGRAPH SEPARATOR
+"\
"; // Escaped U+2029 PARAGRAPH SEPARATOR
+"\u2029"; // Escaped U+2029 PARAGRAPH SEPARATOR

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/directive-paragraph-separator/output.js

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+"before\u2029after"; //     ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char (between 'before' and 'after')
+
+"\u2029"; // Just a U+2029 PARAGRAPH SEPARATOR
+
+"\
"; // Escaped U+2029 PARAGRAPH SEPARATOR
+
+"\u2029"; // Escaped U+2029 PARAGRAPH SEPARATOR

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/string-line-separator/exec.js

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+expect("\u2028".length).toBe(1);
+expect("\u2028").toBe("\u2028");
+
+
+expect("before
after".length).toBe(12);
+expect("before
after").toBe("before\u2028after");
+//            ^ That's a U+2028 LINE SEPARATOR UTF-16 char (between 'before' and 'after')
+
+expect("
".length).toBe(1);
+expect("
").toBe("\u2028");
+//      ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\
".length).toBe(0);
+expect("\
").toBe("");
+//       ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\
".length).toBe(2);
+expect("\\
").toBe("\\\u2028");
+//        ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\
".length).toBe(1);
+expect("\\\
").toBe("\\");
+//         ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\\
".length).toBe(3);
+expect("\\\\
").toBe("\\\\\u2028");
+//          ^ That's a U+2028 LINE SEPARATOR UTF-16 char

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/string-line-separator/input.js

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+expect("\u2028".length).toBe(1);
+expect("\u2028").toBe("\u2028");
+
+
+expect("before
after".length).toBe(12);
+expect("before
after").toBe("before\u2028after");
+//            ^ That's a U+2028 LINE SEPARATOR UTF-16 char (between 'before' and 'after')
+
+expect("
".length).toBe(1);
+expect("
").toBe("\u2028");
+//      ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\
".length).toBe(0);
+expect("\
").toBe("");
+//       ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\
".length).toBe(2);
+expect("\\
").toBe("\\\u2028");
+//        ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\
".length).toBe(1);
+expect("\\\
").toBe("\\");
+//         ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\\
".length).toBe(3);
+expect("\\\\
").toBe("\\\\\u2028");
+//          ^ That's a U+2028 LINE SEPARATOR UTF-16 char

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/string-line-separator/output.js

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+expect("\u2028".length).toBe(1);
+expect("\u2028").toBe("\u2028");
+expect("before\u2028after".length).toBe(12);
+expect("before\u2028after").toBe("before\u2028after"); //            ^ That's a U+2028 LINE SEPARATOR UTF-16 char (between 'before' and 'after')
+
+expect("\u2028".length).toBe(1);
+expect("\u2028").toBe("\u2028"); //      ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\
".length).toBe(0);
+expect("\
").toBe(""); //       ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\u2028".length).toBe(2);
+expect("\\\u2028").toBe("\\\u2028"); //        ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\
".length).toBe(1);
+expect("\\\
").toBe("\\"); //         ^ That's a U+2028 LINE SEPARATOR UTF-16 char
+
+expect("\\\\\u2028".length).toBe(3);
+expect("\\\\\u2028").toBe("\\\\\u2028"); //          ^ That's a U+2028 LINE SEPARATOR UTF-16 char

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/string-paragraph-separator/exec.js

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+expect("\u2029".length).toBe(1);
+expect("\u2029").toBe("\u2029");
+
+
+expect("before
after".length).toBe(12);
+expect("before
after").toBe("before\u2029after");
+//            ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char (between 'before' and 'after')
+
+expect("
".length).toBe(1);
+expect("
").toBe("\u2029");
+//      ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\
".length).toBe(0);
+expect("\
").toBe("");
+//       ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\
".length).toBe(2);
+expect("\\
").toBe("\\\u2029");
+//        ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\
".length).toBe(1);
+expect("\\\
").toBe("\\");
+//         ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\\
".length).toBe(3);
+expect("\\\\
").toBe("\\\\\u2029");
+//          ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/string-paragraph-separator/input.js

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+expect("\u2029".length).toBe(1);
+expect("\u2029").toBe("\u2029");
+
+
+expect("before
after".length).toBe(12);
+expect("before
after").toBe("before\u2029after");
+//            ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char (between 'before' and 'after')
+
+expect("
".length).toBe(1);
+expect("
").toBe("\u2029");
+//      ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\
".length).toBe(0);
+expect("\
").toBe("");
+//       ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\
".length).toBe(2);
+expect("\\
").toBe("\\\u2029");
+//        ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\
".length).toBe(1);
+expect("\\\
").toBe("\\");
+//         ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\\
".length).toBe(3);
+expect("\\\\
").toBe("\\\\\u2029");
+//          ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char

packages/babel-plugin-proposal-json-strings/test/fixtures/json-strings/string-paragraph-separator/output.js

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+expect("\u2029".length).toBe(1);
+expect("\u2029").toBe("\u2029");
+expect("before\u2029after".length).toBe(12);
+expect("before\u2029after").toBe("before\u2029after"); //            ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char (between 'before' and 'after')
+
+expect("\u2029".length).toBe(1);
+expect("\u2029").toBe("\u2029"); //      ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\
".length).toBe(0);
+expect("\
").toBe(""); //       ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\u2029".length).toBe(2);
+expect("\\\u2029").toBe("\\\u2029"); //        ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\
".length).toBe(1);
+expect("\\\
").toBe("\\"); //         ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char
+
+expect("\\\\\u2029".length).toBe(3);
+expect("\\\\\u2029").toBe("\\\\\u2029"); //          ^ That's a U+2029 PARAGRAPH SEPARATOR UTF-16 char

packages/babel-plugin-proposal-json-strings/test/fixtures/options.json

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+{
+  "plugins": ["proposal-json-strings"]
+}

packages/babel-plugin-proposal-json-strings/test/index.js

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+import runner from "@babel/helper-plugin-test-runner";
+
+runner(__dirname);