fix(less): type definitions on options and rootFileInfo (#29631)

* fix(less): type definitions on options and rootFileInfo

Signed-off-by: Richard Lea <chigix@zoho.com>

* fix(less): addition to tests including newly defined options

Signed-off-by: Richard Lea <chigix@zoho.com>

* fix(less): support number for math option

Signed-off-by: Richard Lea <chigix@zoho.com>

types/less/index.d.ts

@@ -1,18 +1,29 @@
-// Type definitions for LESS
+// Type definitions for LESS 3.x
 // Project: http://lesscss.org/
 // Definitions by: Tom Hasner <https://github.com/thasner>
 //                 Pranay Prakash <https://github.com/pranaygp>
 //                 Daniel Waxweiler <https://github.com/dwaxweiler>
+//                 Richard Lea <https://github.com/chigix>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 declare namespace Less {
+    // https://github.com/less/less.js/blob/master/lib/less/import-manager.js#L10
     interface RootFileInfo {
+        /** whether to adjust URL's to be relative */
+        rewriteUrls?: boolean;
+        /** full resolved filename of current file */
         filename: string;
         relativeUrls: boolean;
+        /** path to append to normal URLs for this node */
         rootpath: string;
+        /** path to the current file, absolute */
         currentDirectory: string;
+        /** absolute path to the entry file */
         entryPath: string;
+        /** filename of the base file */
         rootFilename: string;
+        /** whether the file should not be output and only output parts that are referenced */
+        reference: boolean;
     }
 
     class PluginManager {
@@ -59,11 +70,54 @@ declare namespace Less {
         contents: { [fileName: string]: string };
     }
 
+    /**
+     * Reference to:
+     * * https://github.com/less/less.js/blob/master/bin/lessc
+     * * http://lesscss.org/usage/#less-options
+     *
+     * @interface Options
+     */
     interface Options {
         sourceMap?: SourceMapOption;
+        /** Filename of the main file to be passed to less.render() */
         filename?: string;
+        /** The locations for less looking for files in @import rules */
+        paths?: string[];
+        /** True, if run the less parser and just reports errors without any output. */
+        lint?: boolean;
+        /** Pre-load global Less.js plugins */
         plugins?: Plugin[];
-        rootFileInfo?: RootFileInfo;
+        /** @deprecated If true, compress using less built-in compression. */
+        compress?: boolean;
+        strictImports?: boolean;
+        /** If true, allow imports from insecure https hosts. */
+        insecure?: boolean;
+        depends?: boolean;
+        maxLineLen?: number;
+        /** @deprecated If false, No color in compiling. */
+        color?: boolean;
+        /** @deprecated False by default. */
+        ieCompat?: boolean;
+        /** @deprecated If true, enable evaluation of JavaScript inline in `.less` files. */
+        javascriptEnabled?: boolean;
+        /** Whether output file information and line numbers in compiled CSS code. */
+        dumpLineNumbers?: "comment" | string;
+        /** Add a path to every generated import and url in output css files. */
+        rootpath?: string;
+        /** Math mode options for avoiding symbol conficts on math expressions. */
+        math?: 'always' | 'strict' | 'parens-division' | 'parens' | 'strict-legacy' | number;
+        /** If true, stops any warnings from being shown. */
+        silent?: boolean;
+        /** Without this option, Less attempts to guess at the output unit when it does maths. */
+        strictUnits?: boolean;
+        /** Defines a variable that can be referenced by the file. */
+        globalVars?: {
+          [key: string] : string,
+        };
+        /** Puts Var declaration at the end of base file. */
+        modifyVars?: {
+          [key: string] : string,
+        };
     }
 
     interface RenderError {
@@ -109,7 +163,7 @@ interface LessStatic {
     refresh(reload?: boolean, modifyVars?: { [variable: string]: string }, clearFileCache?: boolean): Promise<Less.RefreshOutput>;
 
     version: number[];
-    
+
     watch(): void;
 }
 

types/less/less-tests.ts

@@ -30,8 +30,47 @@ var myPlugin: Less.Plugin = {
     }
 };
 
+/** Reference to: 
+  * https://github.com/less/less.js/blob/master/lib/less/default-options.js
+  */
 var options: Less.Options = {
-    plugins: [myPlugin]
+    plugins: [myPlugin],
+    /** Tells less to generate a sourcemap. */
+    sourceMap: {},
+    /* Inline Javascript - @plugin still allowed */
+    javascriptEnabled: false,
+    /* Outputs a makefile import dependency list to stdout. */
+    depends: false,
+    /** (DEPRECATED) This does not utilise all the tricks of css compression. */
+    compress: false,
+    /* Runs the less parser and just reports errors without any output. */
+    lint: false,
+    /** Less will look for the file in @import rules through locations here. */
+    paths: [],
+    /* color output in the terminal */
+    color: true,
+    /** See: https://github.com/less/less.js/issues/656 */
+    strictImports: false,
+    /* Allow Imports from Insecure HTTPS Hosts */
+    insecure: true,
+    /** Add a path to every generated import and url in your css */
+    rootpath: '',
+    /** 
+      * How to process math
+      * 0 always           - eagerly try to solve all operations
+      * 1 parens-division  - require parens for division "/"
+      * 2 parens | strict  - require parens for all operations
+      * 3 strict-legacy    - legacy strict behavior (super-strict)
+      * https://github.com/less/less.js/blob/master/lib/less/constants.js#L2
+      * https://github.com/less/less.js/blob/master/lib/less/utils.js#L54
+    */
+    math: 0,
+    /* Guess at the output unit when it does maths. */
+    strictUnits: false,
+    /** Put declaration at the top of base less file. */
+    globalVars: null,
+    /** Put the declaration at the end of base file. */
+    modifyVars: null
 };
 
 less.render("h1 { background: red; }", options);