Add macros entry to markdown-math configuration (microsoft#180458)

section.

Author: AlbertHilb

extensions/markdown-math/package.json

@@ -80,6 +80,13 @@
             "type": "boolean",
             "default": true,
             "description": "%config.markdown.math.enabled%"
+          },
+          "markdown.math.macros": {
+            "type": "object",
+            "additionalProperties": { "type": "string" },
+            "default": {},
+            "description": "%config.markdown.math.macros%",
+            "scope": "resource"
           }
         }
       }

extensions/markdown-math/package.nls.json

@@ -1,5 +1,6 @@
 {
 	"displayName": "Markdown Math",
 	"description": "Adds math support to Markdown in notebooks.",
-	"config.markdown.math.enabled": "Enable/disable rendering math in the built-in Markdown preview."
+	"config.markdown.math.enabled": "Enable/disable rendering math in the built-in Markdown preview.",
+	"config.markdown.math.macros": "A collection of custom macros. Each macro is a key-value pair where the key is a new command name and the value is the expansion of the macro."
 }

extensions/markdown-math/src/extension.ts

@@ -6,16 +6,21 @@ import * as vscode from 'vscode';
 
 declare function require(path: string): any;
 
-const enabledSetting = 'markdown.math.enabled';
+const markdownMathSetting = 'markdown.math';
 
 export function activate(context: vscode.ExtensionContext) {
 	function isEnabled(): boolean {
 		const config = vscode.workspace.getConfiguration('markdown');
 		return config.get<boolean>('math.enabled', true);
 	}
 
+	function getMacros(): { [key: string]: string } {
+		const config = vscode.workspace.getConfiguration('markdown');
+		return config.get<{ [key: string]: string }>('math.macros', {});
+	}
+
 	vscode.workspace.onDidChangeConfiguration(e => {
-		if (e.affectsConfiguration(enabledSetting)) {
+		if (e.affectsConfiguration(markdownMathSetting)) {
 			vscode.commands.executeCommand('markdown.api.reloadPlugins');
 		}
 	}, undefined, context.subscriptions);
@@ -24,8 +29,11 @@ export function activate(context: vscode.ExtensionContext) {
 		extendMarkdownIt(md: any) {
 			if (isEnabled()) {
 				const katex = require('@vscode/markdown-it-katex');
-				const options = { globalGroup: true, macros: {} };
-				md.core.ruler.push('reset-katex-macros', () => { options.macros = {}; });
+				const settingsMacros = getMacros();
+				const options = { globalGroup: true, macros: { ...settingsMacros } };
+				md.core.ruler.push('reset-katex-macros', () => {
+					options.macros = { ...settingsMacros };
+				});
 				return md.use(katex, options);
 			}
 			return md;