This pr causes console spam in our case for when we hover a comment on the first line. See obi1kenobi/trustfall#285 for more context.

What does this pr do?

Fixes an off-by-one bug that caused console spam when hovering things in the first line of a graphql file. This occurs because monaco's toGraphQLPosition() from monaco-graphql returns 0-based line/col numbers and getRange() from graphql-language-service expects 1-based line/col numbers.

Why is this the right fix?
We have a 0-indexed row/col. To see this for myself, I put a console.log() after this line. I then hovered the first character on the first line. I see 0,0 printed, and this is after we subtract 1 from both line/col in toGraphQLPosition(), so we definitely have a 0-indexed number.

getRange() takes in a SourceLocation, however that's an interface, so it's not really obvious whether the line/col is 0-based or 1-based. However, there is a function getLocation() that returns a SourceLocation declared in the same location.d.ts from within the graphql/language repo. So taking a look at their getLocation() function, it looks like this:

function getLocation(source, position) {
  let lastLineStart = 0;
  let line = 1;

  for (const match of source.body.matchAll(LineRegExp)) {
    typeof match.index === 'number' || (0, _invariant.invariant)(false);

    if (match.index >= position) {
      break;
    }

    lastLineStart = match.index + match[0].length;
    line += 1;
  }

  return {
    line,
    column: position + 1 - lastLineStart,
  };
}

When I saw that, it became clear that this line is 1-indexed, and the + 1 in the column leads me to believe this number is 1-based too. (if this isn't, please tell me!)