get knit command from settings (#841)

* get knit command from settings

* configuration option description

* Refine description

* Use a default value

* Update comment

Co-authored-by: Kun Ren <renkun@outlook.com>

package.json

@@ -1316,6 +1316,11 @@
           "default": false,
           "markdownDescription": "Should the output file be opened automatically when using knit?\n\nRequires `#r.rmarkdown.knit.useBackgroundProcess#` to be set to `true`."
         },
+        "r.rmarkdown.knit.command": {
+          "type": "string",
+          "default": "rmarkdown::render",
+          "markdownDescription": "Command used to knit a Rmd file if not specified by the frontmatter."
+        },
         "r.rmarkdown.knit.defaults.knitWorkingDirectory": {
           "type": "string",
           "default": "document directory",

src/rmarkdown/knit.ts

@@ -105,7 +105,7 @@ export class RMarkdownKnitManager extends RMarkdownManager {
 		}
 
 		// precedence:
-		// knit > site > none
+		// knit > site > configuration
 		if (yamlParams?.['knit']) {
 			const knitParam = yamlParams['knit'];
 			knitCommand = outputFormat ?
@@ -116,9 +116,10 @@ export class RMarkdownKnitManager extends RMarkdownManager {
 				`rmarkdown::render_site(${docPath}, output_format = '${outputFormat}')` :
 				`rmarkdown::render_site(${docPath})`;
 		} else {
+			const cmd = util.config().get<string>('rmarkdown.knit.command');
 			knitCommand = outputFormat ?
-				`rmarkdown::render(${docPath}, output_format = '${outputFormat}')` :
-				`rmarkdown::render(${docPath})`;
+				`${cmd}(${docPath}, output_format = '${outputFormat}')` :
+				`${cmd}(${docPath})`;
 		}
 
 		return knitCommand.replace(/['"]/g, '\'');