It is quick memo to fix TS7053 error, it took a while to fix it on other day. Here is a example code.

interface PointCondition {
        pleasurePoint: number;
        steamerLane: number;
};

const state: PointCondition = { 
        pleasurePoint: 88, 
        steamerLane: 92, 
};

function getCondition(key: string) : number {
        return state[key];
};

Object.keys(state).forEach(function(key){
  return console.log( getCondition(key) );
})

"strict": true in tsconfig.json

If you try to compile this example code with tsc command, you get

- error TS7053: Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'PointCondition'.
  No index signature with a parameter of type 'string' was found on type 'PointCondition'.

How to fix TS7053

When I first saw this, I specify key: string for the argument, why do I a get error?
I did online search and couple of tests and found out I need to limit strings of key.

return state[key as keyof PointCondition ];

Here is compilable code.

interface PointCondition {
        pleasurePoint: number;
        steamerLane: number;
};

const state: PointCondition = { 
        pleasurePoint: 88, 
        steamerLane: 92, 
};

function getCondition(key: string) : number {
        return state[key as keyof PointCondition ];
};

Object.keys(state).forEach(function(key){
  return console.log( getCondition(key) );
})

Recources

https://github.com/microsoft/TypeScript/issues/36962