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README.md

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+# JSON Edit
+
+Easily change (nested) properties in a JSON files, keeping the original formatting.
+
+The code is extracted from the VSCode source, which uses this functionality to alter the settings.json file when settings are changed through the user interface.
+
+## Usage
+
+```typescript
+import {
+	applyEdits,
+	getFormattingOptions,
+	setProperty,
+} from "@popup-io/json-edit";
+import * as fs from "fs";
+
+const input = fs.readFileSync("package.json", "utf8");
+
+const formattingOptions = getFormattingOptions(input);
+const edit = setProperty(input, ["type"], "module", formattingOptions);
+const output = applyEdits(input, edit);
+
+fs.writeFileSync("package.json", output, "utf8");
+```
+
+## API
+
+### _**getFormattingOptions**(**text**: string): FormattingOptions_
+
+Input the JSON file contents to detect how the file is formatted.
+
+Returns an object with these properties:
+
+- `insertSpaces` (boolean) - Is indentation based on spaces?
+- `tabSize` (number) - If indentation is based on spaces (`insertSpaces` = true), then what is the number of spaces that make an indent?
+- `eol` (string) - The default 'end of line' character. If not set, '\n' is used as default.
+
+### _**setProperty**(**text**: string, **originalPath**: JSONPath, **value**: any, **formattingOptions**: FormattingOptions, **getInsertionIndex**?: (properties: string[]) => number): Edit[];_
+
+Detect what needs to be changed in a JSON file, to set or change a property to a certain value.
+
+A nested property can be changed by passing an array to `originalPath`.
+
+The returned value can be passed to `applyEdits` to get the new file contents.
+
+### _**removeProperty**(**text**: string, **path**: JSONPath, **formattingOptions**: FormattingOptions): Edit[]_
+
+Same as `setProperty`, but removes a property instead of adding/changing one.
+
+### _**applyEdits**(**text**: string, **edits**: Edit[]): string_
+
+Change the file contents by applying one or more edits. Returns the new file contents.
+
+## License
+
+This source code is available to everyone under the standard MIT license, just like VSCode.