approvals/lib/Utilities/Logger/LoggingInstance.ts

Approval Tests Library - Capturing Human Intelligence

import { StringWrapper } from "./StringWrapper";

class Toggles {
  public queries: boolean;
  public messages: boolean;
  public variables: boolean;
  public hourglass: boolean;
  public events: boolean;
  public markers: boolean;

  constructor(show: boolean) {
    this.queries = show;
    this.messages = show;
    this.variables = show;
    this.hourglass = show;
    this.markers = show;
    this.events = show;
  }
}

function printType(value: any) {
  return `<${value.constructor.name}>`;
}

function getCallingMethod(additional_stack: number) {
  const re = /at ([^(]+) \(/g;
  const stack = `${new Error().stack}`;
  const lines = stack.split("\n");
  const stackDepth = 2 + additional_stack;
  const line = lines[stackDepth];
  const aRegexResult = re.exec(line) ?? [];
  const name = aRegexResult[1] || aRegexResult[2];
  return name;
}

export class LoggingInstance {
  logger: (text: string) => void;
  private counter: number = 0;
  private tabs: number = 0;
  private toggles = new Toggles(true);
  public logStackTraces: boolean = true;
  private logWithTimestamps: boolean = true;
  public timer: () => Date;
  private previousTimestamp: Date | null = null;

  constructor() {
    this.logger = (s) => process.stdout.write(s);
    this.timer = () => new Date();
  }

  logToString(): StringWrapper {
    const stringWrapper = new StringWrapper();
    this.logWithTimestamps = false;
    this.logStackTraces = false;
    this.logger = (t) => stringWrapper.append(t);
    return stringWrapper;
  }

  useMarkers<T>(
    additional_stack: number,
    code: () => T,
    parameters: string | (() => string) = "",
    logReturnValue: boolean = false,
  ): T {
    if (!this.toggles.markers) {
      return code();
    }
    const name = getCallingMethod(additional_stack + 1);
    let parameterText = "";
    if (typeof parameters === "function") {
      parameterText = parameters();
    } else {
      parameterText = parameters;
    }
    this.logLine(`=> ${name}(${parameterText})`);
    const returnValue = this.withTabbing(code);
    if (typeof parameters === "function") {
      parameterText = parameters();
    } else {
      parameterText = "";
    }
    let returnText = "";
    if (logReturnValue) {
      returnText = `: ${returnValue}`;
    }
    this.logLine(`<= ${name}(${parameterText})${returnText}`);
    return returnValue;
  }

  variable(name: string, value: any, showTypes: boolean) {
    if (!this.toggles.variables) {
      return;
    }

    let toType = (v: any, s = "") => "";
    if (showTypes) {
      toType = (value, spacing = " ") => `${spacing}${printType(value)}`;
    }

    if (Array.isArray(value)) {
      this.logLine(
        `variable: ${name}${toType(value, "")}.length = ${value.length}`,
      );
      this.withTabbing(() => {
        value.forEach((v, i) => {
          this.logger(`${this.getTabs()}${name}[${i}] = ${v}${toType(v)}\n`);
        });
      });
    } else {
      this.logLine(`variable: ${name} = ${value}${toType(value)}`);
    }
  }

  private logLine(text: string, use_timestamps: boolean = true) {
    if (this.counter != 0) {
      this.logger("\n");
    }
    this.counter = 0;
    const timestamp = use_timestamps ? this.getTimestamp() : "";
    const output_message = `${timestamp}${this.getTabs()}${text}\n`;
    this.logger(output_message);
  }

  private getTabs() {
    return "  ".repeat(this.tabs);
  }

  private withTabbing<T>(code: () => T): T {
    this.tabs += 1;
    const returnValue = code();
    this.tabs -= 1;
    return returnValue;
  }

  hourglass() {
    if (!this.toggles.hourglass) {
      return;
    }

    this.counter += 1;
    if (this.counter == 1) {
      this.logger(`${this.getTabs()}.`);
    } else if (this.counter == 100) {
      this.logger("10\n");
      this.counter = 0;
    } else if (this.counter % 10 == 0) {
      const digit = this.counter / 10;
      this.logger(`${digit}`);
    } else {
      this.logger(".");
    }
  }

  showAll(show: boolean) {
    this.toggles = new Toggles(show);
  }

  event(event_name: string) {
    if (!this.toggles.events) {
      return;
    }
    this.logLine(`event: ${event_name}`);
  }

  showQueries(show: boolean) {
    this.toggles.queries = show;
  }

  showMarkers(show: boolean) {
    this.toggles.markers = show;
  }

  showEvents(show: boolean) {
    this.toggles.events = show;
  }

  showMessages(show: boolean) {
    this.toggles.messages = show;
  }

  showVariables(show: boolean) {
    this.toggles.variables = show;
  }

  showHourglass(show: boolean) {
    this.toggles.hourglass = show;
  }

  warning(exception: Error | string) {
    const warning_stars = "*".repeat(91);
    const text = null;
    this.logLine(warning_stars, false);
    if (this.logWithTimestamps) {
      this.logLine("", true);
    }
    if (text) {
      this.logLine(`Message:${text}`, false);
    }
    if (exception) {
      let stack_trace = "";
      if (this.logStackTraces) {
        // todo: grab stack trace
        stack_trace = exception.toString();
      } else {
        stack_trace = `${exception}`;
      }
      this.logLine(stack_trace, false);
    }
    this.logLine(warning_stars, false);
  }

  query(queryText: string) {
    if (!this.toggles.queries) {
      return;
    }
    this.logLine(`Sql: ${queryText}`);
  }

  message(messageText: string) {
    if (!this.toggles.messages) {
      return;
    }
    this.logLine(`message: ${messageText}`);
  }

  showTimestamps(show: boolean) {
    this.logWithTimestamps = show;
  }

  private getTimestamp() {
    if (!this.logWithTimestamps) {
      return "";
    }

    const time1 = this.timer();
    const time = time1.toISOString();
    let diff_millseconds = 0;
    if (this.previousTimestamp != null) {
      diff_millseconds = time1.getTime() - this.previousTimestamp.getTime();
    }
    const diff_display = `~${String(diff_millseconds).padStart(6, "0")}ms`;
    let time_text = `${time}`.replace("T", " ").substring(0, 19);
    const timestamp = `[${time_text} ${diff_display}] `;
    this.previousTimestamp = time1;
    return timestamp;
  }
}