Set programmatically jsonValidation for dynamic mapping

Question

I am creating a new vscode extension, and I need to extend the standard usage of the jsonValidation system already present in vscode.

Note : I am talking about the system defined in package.json :

"contributes" : {
    "languages": [
        {
            "id" : "yml", 
            "filenamePatterns": ["module.service"]
        },
        {
            "id" : "json", 
            "filenamePatterns": ["module.*"]
        }
    ],
    "jsonValidation": [
        {
            "fileMatch": "module.test",
            "url": "./resources/test.schema"
        }
    ]
}

Now, I need to create a dynamic mapping, where the json fields filematch/url are defined from some internal rules (like version and other internal stuff). The standard usage is static : one fileMatch -> one schema.

I want for example to read the version from the json file to validate, and set the schema after that :

{
    "version" : "1.1"
}

validation schema must be test-schema.1.1 instead of test-schema.1.0

note : The question is only about the modification of the configuration provided by package.json from the extensions.ts

Thanks for the support

Answer 1

** EDIT since the previous solution was not working in all cases

There is one solution to modify the package.json at the activating of the function.

export function activate(context: vscode.ExtensionContext) {
    const myPlugin = vscode.extensions.getExtension("your.plugin.id");
    if (!myPlugin)
    {
        throw new Error("Composer plugin is not found...")
    }

    // Get the current workspace path to found the schema later.
    const folderPath = vscode.workspace.workspaceFolders;
    if (!folderPath)
    {
        return;
    }
    const baseUri : vscode.Uri = folderPath[0].uri;

    let packageJSON = myPlugin.packageJSON;
    if (packageJSON && packageJSON.contributes && packageJSON.contributes.jsonValidation)
    {
        let jsonValidation = packageJSON.contributes.jsonValidation;
        const schemaUri : vscode.Uri =  vscode.Uri.joinPath(baseUri, "/schema/value-0.3.0.json-schema");            
        const schema = new JsonSchemaMatch("value.ospp", schemaUri)
        jsonValidation.push(schema);
    }
}

And the json schema class

class JsonSchemaMatch 
{
    fileMatch: string;
    url : string;

    constructor(fileMatch : string, url: vscode.Uri) 
    {
        this.fileMatch = fileMatch;
        this.url = url.path;
    }
}

Another important information is the loading of the element of contributes is not reread after modification, for example

class Language 
{
    id: string;
    filenamePatterns : string[];

    constructor(id : string, filenamePatterns: string[]) 
    {
        this.id = id;
        this.filenamePatterns = filenamePatterns;
    }
}

if (packageJSON && packageJSON.contributes && packageJSON.contributes.languages)
    {
        let languages : Language[] = packageJSON.contributes.languages;
        for (let language of languages) {
            if (language.id == "json") {
                language.filenamePatterns.push("test.my-json-type")
            }
        }
    }

This change has no effect, since the loading of file association is already done (I have not dig for the reason, but I think this is the case)

In this case, creating a settings.json in the workspace directory can do the job:

settings.json

{
  "files.associations": {
    "target.snmp": "json",
    "stack.cfg": "json"
  }
}

Be aware that the settings.json can be created by the user with legitimate reason, so don't override it, just fill it.