281 lines
11 KiB
JavaScript
281 lines
11 KiB
JavaScript
const getAllAliases = (name, aliases) => {
|
|
const _aliases = [];
|
|
if (name) {
|
|
_aliases.push(name);
|
|
}
|
|
if (aliases) {
|
|
for (const alias of aliases) {
|
|
_aliases.push(alias);
|
|
}
|
|
}
|
|
return _aliases;
|
|
};
|
|
const getMiddlewareNameWithAliases = (name, aliases) => {
|
|
return `${name || "anonymous"}${aliases && aliases.length > 0 ? ` (a.k.a. ${aliases.join(",")})` : ""}`;
|
|
};
|
|
export const constructStack = () => {
|
|
let absoluteEntries = [];
|
|
let relativeEntries = [];
|
|
let identifyOnResolve = false;
|
|
const entriesNameSet = new Set();
|
|
const sort = (entries) => entries.sort((a, b) => stepWeights[b.step] - stepWeights[a.step] ||
|
|
priorityWeights[b.priority || "normal"] - priorityWeights[a.priority || "normal"]);
|
|
const removeByName = (toRemove) => {
|
|
let isRemoved = false;
|
|
const filterCb = (entry) => {
|
|
const aliases = getAllAliases(entry.name, entry.aliases);
|
|
if (aliases.includes(toRemove)) {
|
|
isRemoved = true;
|
|
for (const alias of aliases) {
|
|
entriesNameSet.delete(alias);
|
|
}
|
|
return false;
|
|
}
|
|
return true;
|
|
};
|
|
absoluteEntries = absoluteEntries.filter(filterCb);
|
|
relativeEntries = relativeEntries.filter(filterCb);
|
|
return isRemoved;
|
|
};
|
|
const removeByReference = (toRemove) => {
|
|
let isRemoved = false;
|
|
const filterCb = (entry) => {
|
|
if (entry.middleware === toRemove) {
|
|
isRemoved = true;
|
|
for (const alias of getAllAliases(entry.name, entry.aliases)) {
|
|
entriesNameSet.delete(alias);
|
|
}
|
|
return false;
|
|
}
|
|
return true;
|
|
};
|
|
absoluteEntries = absoluteEntries.filter(filterCb);
|
|
relativeEntries = relativeEntries.filter(filterCb);
|
|
return isRemoved;
|
|
};
|
|
const cloneTo = (toStack) => {
|
|
absoluteEntries.forEach((entry) => {
|
|
toStack.add(entry.middleware, { ...entry });
|
|
});
|
|
relativeEntries.forEach((entry) => {
|
|
toStack.addRelativeTo(entry.middleware, { ...entry });
|
|
});
|
|
toStack.identifyOnResolve?.(stack.identifyOnResolve());
|
|
return toStack;
|
|
};
|
|
const expandRelativeMiddlewareList = (from) => {
|
|
const expandedMiddlewareList = [];
|
|
from.before.forEach((entry) => {
|
|
if (entry.before.length === 0 && entry.after.length === 0) {
|
|
expandedMiddlewareList.push(entry);
|
|
}
|
|
else {
|
|
expandedMiddlewareList.push(...expandRelativeMiddlewareList(entry));
|
|
}
|
|
});
|
|
expandedMiddlewareList.push(from);
|
|
from.after.reverse().forEach((entry) => {
|
|
if (entry.before.length === 0 && entry.after.length === 0) {
|
|
expandedMiddlewareList.push(entry);
|
|
}
|
|
else {
|
|
expandedMiddlewareList.push(...expandRelativeMiddlewareList(entry));
|
|
}
|
|
});
|
|
return expandedMiddlewareList;
|
|
};
|
|
const getMiddlewareList = (debug = false) => {
|
|
const normalizedAbsoluteEntries = [];
|
|
const normalizedRelativeEntries = [];
|
|
const normalizedEntriesNameMap = {};
|
|
absoluteEntries.forEach((entry) => {
|
|
const normalizedEntry = {
|
|
...entry,
|
|
before: [],
|
|
after: [],
|
|
};
|
|
for (const alias of getAllAliases(normalizedEntry.name, normalizedEntry.aliases)) {
|
|
normalizedEntriesNameMap[alias] = normalizedEntry;
|
|
}
|
|
normalizedAbsoluteEntries.push(normalizedEntry);
|
|
});
|
|
relativeEntries.forEach((entry) => {
|
|
const normalizedEntry = {
|
|
...entry,
|
|
before: [],
|
|
after: [],
|
|
};
|
|
for (const alias of getAllAliases(normalizedEntry.name, normalizedEntry.aliases)) {
|
|
normalizedEntriesNameMap[alias] = normalizedEntry;
|
|
}
|
|
normalizedRelativeEntries.push(normalizedEntry);
|
|
});
|
|
normalizedRelativeEntries.forEach((entry) => {
|
|
if (entry.toMiddleware) {
|
|
const toMiddleware = normalizedEntriesNameMap[entry.toMiddleware];
|
|
if (toMiddleware === undefined) {
|
|
if (debug) {
|
|
return;
|
|
}
|
|
throw new Error(`${entry.toMiddleware} is not found when adding ` +
|
|
`${getMiddlewareNameWithAliases(entry.name, entry.aliases)} ` +
|
|
`middleware ${entry.relation} ${entry.toMiddleware}`);
|
|
}
|
|
if (entry.relation === "after") {
|
|
toMiddleware.after.push(entry);
|
|
}
|
|
if (entry.relation === "before") {
|
|
toMiddleware.before.push(entry);
|
|
}
|
|
}
|
|
});
|
|
const mainChain = sort(normalizedAbsoluteEntries)
|
|
.map(expandRelativeMiddlewareList)
|
|
.reduce((wholeList, expandedMiddlewareList) => {
|
|
wholeList.push(...expandedMiddlewareList);
|
|
return wholeList;
|
|
}, []);
|
|
return mainChain;
|
|
};
|
|
const stack = {
|
|
add: (middleware, options = {}) => {
|
|
const { name, override, aliases: _aliases } = options;
|
|
const entry = {
|
|
step: "initialize",
|
|
priority: "normal",
|
|
middleware,
|
|
...options,
|
|
};
|
|
const aliases = getAllAliases(name, _aliases);
|
|
if (aliases.length > 0) {
|
|
if (aliases.some((alias) => entriesNameSet.has(alias))) {
|
|
if (!override)
|
|
throw new Error(`Duplicate middleware name '${getMiddlewareNameWithAliases(name, _aliases)}'`);
|
|
for (const alias of aliases) {
|
|
const toOverrideIndex = absoluteEntries.findIndex((entry) => entry.name === alias || entry.aliases?.some((a) => a === alias));
|
|
if (toOverrideIndex === -1) {
|
|
continue;
|
|
}
|
|
const toOverride = absoluteEntries[toOverrideIndex];
|
|
if (toOverride.step !== entry.step || entry.priority !== toOverride.priority) {
|
|
throw new Error(`"${getMiddlewareNameWithAliases(toOverride.name, toOverride.aliases)}" middleware with ` +
|
|
`${toOverride.priority} priority in ${toOverride.step} step cannot ` +
|
|
`be overridden by "${getMiddlewareNameWithAliases(name, _aliases)}" middleware with ` +
|
|
`${entry.priority} priority in ${entry.step} step.`);
|
|
}
|
|
absoluteEntries.splice(toOverrideIndex, 1);
|
|
}
|
|
}
|
|
for (const alias of aliases) {
|
|
entriesNameSet.add(alias);
|
|
}
|
|
}
|
|
absoluteEntries.push(entry);
|
|
},
|
|
addRelativeTo: (middleware, options) => {
|
|
const { name, override, aliases: _aliases } = options;
|
|
const entry = {
|
|
middleware,
|
|
...options,
|
|
};
|
|
const aliases = getAllAliases(name, _aliases);
|
|
if (aliases.length > 0) {
|
|
if (aliases.some((alias) => entriesNameSet.has(alias))) {
|
|
if (!override)
|
|
throw new Error(`Duplicate middleware name '${getMiddlewareNameWithAliases(name, _aliases)}'`);
|
|
for (const alias of aliases) {
|
|
const toOverrideIndex = relativeEntries.findIndex((entry) => entry.name === alias || entry.aliases?.some((a) => a === alias));
|
|
if (toOverrideIndex === -1) {
|
|
continue;
|
|
}
|
|
const toOverride = relativeEntries[toOverrideIndex];
|
|
if (toOverride.toMiddleware !== entry.toMiddleware || toOverride.relation !== entry.relation) {
|
|
throw new Error(`"${getMiddlewareNameWithAliases(toOverride.name, toOverride.aliases)}" middleware ` +
|
|
`${toOverride.relation} "${toOverride.toMiddleware}" middleware cannot be overridden ` +
|
|
`by "${getMiddlewareNameWithAliases(name, _aliases)}" middleware ${entry.relation} ` +
|
|
`"${entry.toMiddleware}" middleware.`);
|
|
}
|
|
relativeEntries.splice(toOverrideIndex, 1);
|
|
}
|
|
}
|
|
for (const alias of aliases) {
|
|
entriesNameSet.add(alias);
|
|
}
|
|
}
|
|
relativeEntries.push(entry);
|
|
},
|
|
clone: () => cloneTo(constructStack()),
|
|
use: (plugin) => {
|
|
plugin.applyToStack(stack);
|
|
},
|
|
remove: (toRemove) => {
|
|
if (typeof toRemove === "string")
|
|
return removeByName(toRemove);
|
|
else
|
|
return removeByReference(toRemove);
|
|
},
|
|
removeByTag: (toRemove) => {
|
|
let isRemoved = false;
|
|
const filterCb = (entry) => {
|
|
const { tags, name, aliases: _aliases } = entry;
|
|
if (tags && tags.includes(toRemove)) {
|
|
const aliases = getAllAliases(name, _aliases);
|
|
for (const alias of aliases) {
|
|
entriesNameSet.delete(alias);
|
|
}
|
|
isRemoved = true;
|
|
return false;
|
|
}
|
|
return true;
|
|
};
|
|
absoluteEntries = absoluteEntries.filter(filterCb);
|
|
relativeEntries = relativeEntries.filter(filterCb);
|
|
return isRemoved;
|
|
},
|
|
concat: (from) => {
|
|
const cloned = cloneTo(constructStack());
|
|
cloned.use(from);
|
|
cloned.identifyOnResolve(identifyOnResolve || cloned.identifyOnResolve() || (from.identifyOnResolve?.() ?? false));
|
|
return cloned;
|
|
},
|
|
applyToStack: cloneTo,
|
|
identify: () => {
|
|
return getMiddlewareList(true).map((mw) => {
|
|
const step = mw.step ??
|
|
mw.relation +
|
|
" " +
|
|
mw.toMiddleware;
|
|
return getMiddlewareNameWithAliases(mw.name, mw.aliases) + " - " + step;
|
|
});
|
|
},
|
|
identifyOnResolve(toggle) {
|
|
if (typeof toggle === "boolean")
|
|
identifyOnResolve = toggle;
|
|
return identifyOnResolve;
|
|
},
|
|
resolve: (handler, context) => {
|
|
for (const middleware of getMiddlewareList()
|
|
.map((entry) => entry.middleware)
|
|
.reverse()) {
|
|
handler = middleware(handler, context);
|
|
}
|
|
if (identifyOnResolve) {
|
|
console.log(stack.identify());
|
|
}
|
|
return handler;
|
|
},
|
|
};
|
|
return stack;
|
|
};
|
|
const stepWeights = {
|
|
initialize: 5,
|
|
serialize: 4,
|
|
build: 3,
|
|
finalizeRequest: 2,
|
|
deserialize: 1,
|
|
};
|
|
const priorityWeights = {
|
|
high: 3,
|
|
normal: 2,
|
|
low: 1,
|
|
};
|