From 7a3038b982c4d318e146698527070f096591aa4f Mon Sep 17 00:00:00 2001
From: "(quasar) nebula" <qznebula@protonmail.com>
Date: Fri, 16 Feb 2024 09:39:14 -0400
Subject: sugar: move many functions into new #aggregate import

---
 src/util/aggregate.js | 646 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 646 insertions(+)
 create mode 100644 src/util/aggregate.js

(limited to 'src/util/aggregate.js')

diff --git a/src/util/aggregate.js b/src/util/aggregate.js
new file mode 100644
index 0000000..c5d4198
--- /dev/null
+++ b/src/util/aggregate.js
@@ -0,0 +1,646 @@
+import {colors} from './cli.js';
+import {empty, typeAppearance} from './sugar.js';
+
+// Utility function for providing useful interfaces to the JS AggregateError
+// class.
+//
+// Generally, this works by returning a set of interfaces which operate on
+// functions: wrap() takes a function and returns a new function which passes
+// its arguments through and appends any resulting error to the internal error
+// list; call() simplifies this process by wrapping the provided function and
+// then calling it immediately. Once the process for which errors should be
+// aggregated is complete, close() constructs and throws an AggregateError
+// object containing all caught errors (or doesn't throw anything if there were
+// no errors).
+export function openAggregate({
+  // Constructor to use, defaulting to the builtin AggregateError class.
+  // Anything passed here should probably extend from that! May be used for
+  // letting callers programatically distinguish between multiple aggregate
+  // errors.
+  //
+  // This should be provided using the aggregateThrows utility function.
+  [openAggregate.errorClassSymbol]: errorClass = AggregateError,
+
+  // Optional human-readable message to describe the aggregate error, if
+  // constructed.
+  message = '',
+
+  // Optional flag to indicate that this layer of the aggregate error isn't
+  // generally useful outside of developer debugging purposes - it will be
+  // skipped by default when using showAggregate, showing contained errors
+  // inline with other children of this aggregate's parent.
+  //
+  // If set to 'single', it'll be hidden only if there's a single error in the
+  // aggregate (so it's not grouping multiple errors together).
+  translucent = false,
+
+  // Value to return when a provided function throws an error. If this is a
+  // function, it will be called with the arguments given to the function.
+  // (This is primarily useful when wrapping a function and then providing it
+  // to another utility, e.g. array.map().)
+  returnOnFail = null,
+} = {}) {
+  const errors = [];
+
+  const aggregate = {};
+
+  aggregate.wrap =
+    (fn) =>
+    (...args) => {
+      try {
+        return fn(...args);
+      } catch (error) {
+        errors.push(error);
+        return typeof returnOnFail === 'function'
+          ? returnOnFail(...args)
+          : returnOnFail;
+      }
+    };
+
+  aggregate.wrapAsync =
+    (fn) =>
+    (...args) => {
+      return fn(...args).then(
+        (value) => value,
+        (error) => {
+          errors.push(error);
+          return typeof returnOnFail === 'function'
+            ? returnOnFail(...args)
+            : returnOnFail;
+        }
+      );
+    };
+
+  aggregate.push = (error) => {
+    errors.push(error);
+  };
+
+  aggregate.call = (fn, ...args) => {
+    return aggregate.wrap(fn)(...args);
+  };
+
+  aggregate.callAsync = (fn, ...args) => {
+    return aggregate.wrapAsync(fn)(...args);
+  };
+
+  aggregate.nest = (...args) => {
+    return aggregate.call(() => withAggregate(...args));
+  };
+
+  aggregate.nestAsync = (...args) => {
+    return aggregate.callAsync(() => withAggregateAsync(...args));
+  };
+
+  aggregate.map = (...args) => {
+    const parent = aggregate;
+    const {result, aggregate: child} = mapAggregate(...args);
+    parent.call(child.close);
+    return result;
+  };
+
+  aggregate.mapAsync = async (...args) => {
+    const parent = aggregate;
+    const {result, aggregate: child} = await mapAggregateAsync(...args);
+    parent.call(child.close);
+    return result;
+  };
+
+  aggregate.filter = (...args) => {
+    const parent = aggregate;
+    const {result, aggregate: child} = filterAggregate(...args);
+    parent.call(child.close);
+    return result;
+  };
+
+  aggregate.throws = aggregateThrows;
+
+  aggregate.close = () => {
+    if (errors.length) {
+      const error = Reflect.construct(errorClass, [errors, message]);
+
+      if (translucent) {
+        error[Symbol.for('hsmusic.aggregate.translucent')] = translucent;
+      }
+
+      throw error;
+    }
+  };
+
+  return aggregate;
+}
+
+openAggregate.errorClassSymbol = Symbol('error class');
+
+// Utility function for providing {errorClass} parameter to aggregate functions.
+export function aggregateThrows(errorClass) {
+  return {[openAggregate.errorClassSymbol]: errorClass};
+}
+
+// Helper function for allowing both (fn, aggregateOpts) and (aggregateOpts, fn)
+// in aggregate utilities.
+function _reorganizeAggregateArguments(arg1, arg2) {
+  if (typeof arg1 === 'function') {
+    return {fn: arg1, opts: arg2 ?? {}};
+  } else if (typeof arg2 === 'function') {
+    return {fn: arg2, opts: arg1 ?? {}};
+  } else {
+    throw new Error(`Expected a function`);
+  }
+}
+
+// Performs an ordinary array map with the given function, collating into a
+// results array (with errored inputs filtered out) and an error aggregate.
+//
+// Optionally, override returnOnFail to disable filtering and map errored inputs
+// to a particular output.
+//
+// Note the aggregate property is the result of openAggregate(), still unclosed;
+// use aggregate.close() to throw the error. (This aggregate may be passed to a
+// parent aggregate: `parent.call(aggregate.close)`!)
+export function mapAggregate(array, arg1, arg2) {
+  const {fn, opts} = _reorganizeAggregateArguments(arg1, arg2);
+  return _mapAggregate('sync', null, array, fn, opts);
+}
+
+export function mapAggregateAsync(array, arg1, arg2) {
+  const {fn, opts} = _reorganizeAggregateArguments(arg1, arg2);
+  const {promiseAll = Promise.all.bind(Promise), ...remainingOpts} = opts;
+  return _mapAggregate('async', promiseAll, array, fn, remainingOpts);
+}
+
+// Helper function for mapAggregate which holds code common between sync and
+// async versions.
+export function _mapAggregate(mode, promiseAll, array, fn, aggregateOpts) {
+  const failureSymbol = Symbol();
+
+  const aggregate = openAggregate({
+    returnOnFail: failureSymbol,
+    ...aggregateOpts,
+  });
+
+  if (mode === 'sync') {
+    const result = array
+      .map(aggregate.wrap(fn))
+      .filter((value) => value !== failureSymbol);
+    return {result, aggregate};
+  } else {
+    return promiseAll(array.map(aggregate.wrapAsync(fn)))
+      .then((values) => {
+        const result = values.filter((value) => value !== failureSymbol);
+        return {result, aggregate};
+      });
+  }
+}
+
+// Performs an ordinary array filter with the given function, collating into a
+// results array (with errored inputs filtered out) and an error aggregate.
+//
+// Optionally, override returnOnFail to disable filtering errors and map errored
+// inputs to a particular output.
+//
+// As with mapAggregate, the returned aggregate property is not yet closed.
+export function filterAggregate(array, arg1, arg2) {
+  const {fn, opts} = _reorganizeAggregateArguments(arg1, arg2);
+  return _filterAggregate('sync', null, array, fn, opts);
+}
+
+export async function filterAggregateAsync(array, arg1, arg2) {
+  const {fn, opts} = _reorganizeAggregateArguments(arg1, arg2);
+  const {promiseAll = Promise.all.bind(Promise), ...remainingOpts} = opts;
+  return _filterAggregate('async', promiseAll, array, fn, remainingOpts);
+}
+
+// Helper function for filterAggregate which holds code common between sync and
+// async versions.
+function _filterAggregate(mode, promiseAll, array, fn, aggregateOpts) {
+  const failureSymbol = Symbol();
+
+  const aggregate = openAggregate({
+    returnOnFail: failureSymbol,
+    ...aggregateOpts,
+  });
+
+  function filterFunction(value) {
+    // Filter out results which match the failureSymbol, i.e. errored
+    // inputs.
+    if (value === failureSymbol) return false;
+
+    // Always keep results which match the overridden returnOnFail
+    // value, if provided.
+    if (value === aggregateOpts.returnOnFail) return true;
+
+    // Otherwise, filter according to the returned value of the wrapped
+    // function.
+    return value.output;
+  }
+
+  function mapFunction(value) {
+    // Then turn the results back into their corresponding input, or, if
+    // provided, the overridden returnOnFail value.
+    return value === aggregateOpts.returnOnFail ? value : value.input;
+  }
+
+  if (mode === 'sync') {
+    const result = array
+      .map(aggregate.wrap((input, index, array) => {
+        const output = fn(input, index, array);
+        return {input, output};
+      }))
+      .filter(filterFunction)
+      .map(mapFunction);
+
+    return {result, aggregate};
+  } else {
+    return promiseAll(
+      array.map(aggregate.wrapAsync(async (input, index, array) => {
+        const output = await fn(input, index, array);
+        return {input, output};
+      }))
+    ).then((values) => {
+      const result = values.filter(filterFunction).map(mapFunction);
+
+      return {result, aggregate};
+    });
+  }
+}
+
+// Totally sugar function for opening an aggregate, running the provided
+// function with it, then closing the function and returning the result (if
+// there's no throw).
+export function withAggregate(arg1, arg2) {
+  const {fn, opts} = _reorganizeAggregateArguments(arg1, arg2);
+  return _withAggregate('sync', opts, fn);
+}
+
+export function withAggregateAsync(arg1, arg2) {
+  const {fn, opts} = _reorganizeAggregateArguments(arg1, arg2);
+  return _withAggregate('async', opts, fn);
+}
+
+export function _withAggregate(mode, aggregateOpts, fn) {
+  const aggregate = openAggregate(aggregateOpts);
+
+  if (mode === 'sync') {
+    const result = fn(aggregate);
+    aggregate.close();
+    return result;
+  } else {
+    return fn(aggregate).then((result) => {
+      aggregate.close();
+      return result;
+    });
+  }
+}
+
+export const unhelpfulTraceLines = [
+  /sugar/,
+  /node:/,
+  /<anonymous>/,
+];
+
+export function getUsefulTraceLine(trace, {helpful, unhelpful}) {
+  if (!trace) return '';
+
+  for (const traceLine of trace.split('\n')) {
+    if (!traceLine.trim().startsWith('at')) {
+      continue;
+    }
+
+    if (!empty(unhelpful)) {
+      if (unhelpful.some(regex => regex.test(traceLine))) {
+        continue;
+      }
+    }
+
+    if (!empty(helpful)) {
+      for (const regex of helpful) {
+        const match = traceLine.match(regex);
+
+        if (match) {
+          return match[1] ?? traceLine;
+        }
+      }
+
+      continue;
+    }
+
+    return traceLine;
+  }
+
+  return '';
+}
+
+export function showAggregate(topError, {
+  pathToFileURL = f => f,
+  showTraces = true,
+  showTranslucent = showTraces,
+  print = true,
+} = {}) {
+  const getTranslucency = error =>
+    error[Symbol.for('hsmusic.aggregate.translucent')] ?? false;
+
+  const determineCauseHelper = cause => {
+    if (!cause) {
+      return null;
+    }
+
+    const translucency = getTranslucency(cause);
+
+    if (!translucency) {
+      return cause;
+    }
+
+    if (translucency === 'single') {
+      if (cause.errors?.length === 1) {
+        return determineCauseHelper(cause.errors[0]);
+      } else {
+        return cause;
+      }
+    }
+
+    return determineCauseHelper(cause.cause);
+  };
+
+  const determineCause = error =>
+    (showTranslucent
+      ? error.cause ?? null
+      : determineCauseHelper(error.cause));
+
+  const determineErrorsHelper = error => {
+    const translucency = getTranslucency(error);
+
+    if (!translucency) {
+      return [error];
+    }
+
+    if (translucency === 'single' && error.errors?.length >= 2) {
+      return [error];
+    }
+
+    const errors = [];
+
+    if (error.cause) {
+      errors.push(...determineErrorsHelper(error.cause));
+    }
+
+    if (error.errors) {
+      errors.push(...error.errors.flatMap(determineErrorsHelper));
+    }
+
+    return errors;
+  };
+
+  const determineErrors = error =>
+    (showTranslucent
+      ? error.errors ?? null
+      : error.errors?.flatMap(determineErrorsHelper) ?? null);
+
+  const flattenErrorStructure = (error, level = 0) => {
+    const cause = determineCause(error);
+    const errors = determineErrors(error);
+
+    return {
+      level,
+
+      kind: error.constructor.name,
+      message: error.message,
+
+      trace:
+        (error[Symbol.for(`hsmusic.aggregate.traceFrom`)]
+          ? error[Symbol.for(`hsmusic.aggregate.traceFrom`)].stack
+          : error.stack),
+
+      cause:
+        (cause
+          ? flattenErrorStructure(cause, level + 1)
+          : null),
+
+      errors:
+        (errors
+          ? errors.map(error => flattenErrorStructure(error, level + 1))
+          : null),
+
+      options: {
+        alwaysTrace:
+          error[Symbol.for(`hsmusic.aggregate.alwaysTrace`)],
+
+        helpfulTraceLines:
+          error[Symbol.for(`hsmusic.aggregate.helpfulTraceLines`)],
+
+        unhelpfulTraceLines:
+          error[Symbol.for(`hsmusic.aggregate.unhelpfulTraceLines`)],
+      }
+    };
+  };
+
+  const recursive = ({
+    level,
+    kind,
+    message,
+    trace,
+    cause,
+    errors,
+    options: {
+      alwaysTrace,
+      helpfulTraceLines: ownHelpfulTraceLines,
+      unhelpfulTraceLines: ownUnhelpfulTraceLines,
+    },
+  }, index, apparentSiblings) => {
+    const subApparentSiblings =
+      (cause && errors
+        ? [cause, ...errors]
+     : cause
+        ? [cause]
+     : errors
+        ? errors
+        : []);
+
+    const anythingHasErrorsThisLayer =
+      apparentSiblings.some(({errors}) => !empty(errors));
+
+    const messagePart =
+      message || `(no message)`;
+
+    const kindPart =
+      kind || `unnamed kind`;
+
+    let headerPart =
+      (showTraces
+        ? `[${kindPart}] ${messagePart}`
+     : errors
+        ? `[${messagePart}]`
+     : anythingHasErrorsThisLayer
+        ? ` ${messagePart}`
+        : messagePart);
+
+    if (showTraces || alwaysTrace) {
+      const traceLine =
+        getUsefulTraceLine(trace, {
+          unhelpful:
+            (ownUnhelpfulTraceLines
+              ? unhelpfulTraceLines.concat(ownUnhelpfulTraceLines)
+              : unhelpfulTraceLines),
+
+          helpful:
+            (ownHelpfulTraceLines
+              ? ownHelpfulTraceLines
+              : null),
+        });
+
+      const tracePart =
+        (traceLine
+          ? '- ' +
+            traceLine
+              .trim()
+              .replace(/file:\/\/.*\.js/, (match) => pathToFileURL(match))
+          : '(no stack trace)');
+
+      headerPart += ` ${colors.dim(tracePart)}`;
+    }
+
+    const head1 = level % 2 === 0 ? '\u21aa' : colors.dim('\u21aa');
+    const bar1 = ' ';
+
+    const causePart =
+      (cause
+        ? recursive(cause, 0, subApparentSiblings)
+            .split('\n')
+            .map((line, i) => i === 0 ? ` ${head1} ${line}` : ` ${bar1} ${line}`)
+            .join('\n')
+        : '');
+
+    const head2 = level % 2 === 0 ? '\u257f' : colors.dim('\u257f');
+    const bar2 = level % 2 === 0 ? '\u2502' : colors.dim('\u254e');
+
+    const errorsPart =
+      (errors
+        ? errors
+            .map((error, index) => recursive(error, index + 1, subApparentSiblings))
+            .flatMap(str => str.split('\n'))
+            .map((line, i) => i === 0 ? ` ${head2} ${line}` : ` ${bar2} ${line}`)
+            .join('\n')
+        : '');
+
+    return [headerPart, errorsPart, causePart].filter(Boolean).join('\n');
+  };
+
+  const structure = flattenErrorStructure(topError);
+  const message = recursive(structure, 0, [structure]);
+
+  if (print) {
+    console.error(message);
+  } else {
+    return message;
+  }
+}
+
+export function annotateError(error, ...callbacks) {
+  for (const callback of callbacks) {
+    error = callback(error) ?? error;
+  }
+
+  return error;
+}
+
+export function annotateErrorWithIndex(error, index) {
+  return Object.assign(error, {
+    [Symbol.for('hsmusic.annotateError.indexInSourceArray')]:
+      index,
+
+    message:
+      `(${colors.yellow(`#${index + 1}`)}) ` +
+      error.message,
+  });
+}
+
+export function annotateErrorWithFile(error, file) {
+  return Object.assign(error, {
+    [Symbol.for('hsmusic.annotateError.file')]:
+      file,
+
+    message:
+      error.message +
+      (error.message.includes('\n') ? '\n' : ' ') +
+      `(file: ${colors.bright(colors.blue(file))})`,
+  });
+}
+
+export function asyncAdaptiveDecorateError(fn, callback) {
+  if (typeof callback !== 'function') {
+    throw new Error(`Expected callback to be a function, got ${typeAppearance(callback)}`);
+  }
+
+  const syncDecorated = function (...args) {
+    try {
+      return fn(...args);
+    } catch (caughtError) {
+      throw callback(caughtError, ...args);
+    }
+  };
+
+  const asyncDecorated = async function(...args) {
+    try {
+      return await fn(...args);
+    } catch (caughtError) {
+      throw callback(caughtError, ...args);
+    }
+  };
+
+  syncDecorated.async = asyncDecorated;
+
+  return syncDecorated;
+}
+
+export function decorateError(fn, callback) {
+  return asyncAdaptiveDecorateError(fn, callback);
+}
+
+export function asyncDecorateError(fn, callback) {
+  return asyncAdaptiveDecorateError(fn, callback).async;
+}
+
+export function decorateErrorWithAnnotation(fn, ...annotationCallbacks) {
+  return asyncAdaptiveDecorateError(fn,
+    (caughtError, ...args) =>
+      annotateError(caughtError,
+        ...annotationCallbacks
+          .map(callback => error => callback(error, ...args))));
+}
+
+export function decorateErrorWithIndex(fn) {
+  return decorateErrorWithAnnotation(fn,
+    (caughtError, _value, index) =>
+      annotateErrorWithIndex(caughtError, index));
+}
+
+export function decorateErrorWithCause(fn, cause) {
+  return asyncAdaptiveDecorateError(fn,
+    (caughtError) =>
+      Object.assign(caughtError, {cause}));
+}
+
+export function asyncDecorateErrorWithAnnotation(fn, ...annotationCallbacks) {
+  return decorateErrorWithAnnotation(fn, ...annotationCallbacks).async;
+}
+
+export function asyncDecorateErrorWithIndex(fn) {
+  return decorateErrorWithIndex(fn).async;
+}
+
+export function asyncDecorateErrorWithCause(fn, cause) {
+  return decorateErrorWithCause(fn, cause).async;
+}
+
+export function conditionallySuppressError(conditionFn, callbackFn) {
+  return (...args) => {
+    try {
+      return callbackFn(...args);
+    } catch (error) {
+      if (conditionFn(error, ...args) === true) {
+        return;
+      }
+
+      throw error;
+    }
+  };
+}
-- 
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