aws-ddk-core
Version:
The AWS DataOps Development Kit is an open source development framework for customers that build data workflows and modern data architecture on AWS.
179 lines (175 loc) • 6.24 kB
JavaScript
;
var identity = require('../nodes/identity.js');
var visit = require('../visit.js');
const escapeChars = {
'!': '%21',
',': '%2C',
'[': '%5B',
']': '%5D',
'{': '%7B',
'}': '%7D'
};
const escapeTagName = (tn) => tn.replace(/[!,[\]{}]/g, ch => escapeChars[ch]);
class Directives {
constructor(yaml, tags) {
/**
* The directives-end/doc-start marker `---`. If `null`, a marker may still be
* included in the document's stringified representation.
*/
this.docStart = null;
/** The doc-end marker `...`. */
this.docEnd = false;
this.yaml = Object.assign({}, Directives.defaultYaml, yaml);
this.tags = Object.assign({}, Directives.defaultTags, tags);
}
clone() {
const copy = new Directives(this.yaml, this.tags);
copy.docStart = this.docStart;
return copy;
}
/**
* During parsing, get a Directives instance for the current document and
* update the stream state according to the current version's spec.
*/
atDocument() {
const res = new Directives(this.yaml, this.tags);
switch (this.yaml.version) {
case '1.1':
this.atNextDocument = true;
break;
case '1.2':
this.atNextDocument = false;
this.yaml = {
explicit: Directives.defaultYaml.explicit,
version: '1.2'
};
this.tags = Object.assign({}, Directives.defaultTags);
break;
}
return res;
}
/**
* @param onError - May be called even if the action was successful
* @returns `true` on success
*/
add(line, onError) {
if (this.atNextDocument) {
this.yaml = { explicit: Directives.defaultYaml.explicit, version: '1.1' };
this.tags = Object.assign({}, Directives.defaultTags);
this.atNextDocument = false;
}
const parts = line.trim().split(/[ \t]+/);
const name = parts.shift();
switch (name) {
case '%TAG': {
if (parts.length !== 2) {
onError(0, '%TAG directive should contain exactly two parts');
if (parts.length < 2)
return false;
}
const [handle, prefix] = parts;
this.tags[handle] = prefix;
return true;
}
case '%YAML': {
this.yaml.explicit = true;
if (parts.length !== 1) {
onError(0, '%YAML directive should contain exactly one part');
return false;
}
const [version] = parts;
if (version === '1.1' || version === '1.2') {
this.yaml.version = version;
return true;
}
else {
const isValid = /^\d+\.\d+$/.test(version);
onError(6, `Unsupported YAML version ${version}`, isValid);
return false;
}
}
default:
onError(0, `Unknown directive ${name}`, true);
return false;
}
}
/**
* Resolves a tag, matching handles to those defined in %TAG directives.
*
* @returns Resolved tag, which may also be the non-specific tag `'!'` or a
* `'!local'` tag, or `null` if unresolvable.
*/
tagName(source, onError) {
if (source === '!')
return '!'; // non-specific tag
if (source[0] !== '!') {
onError(`Not a valid tag: ${source}`);
return null;
}
if (source[1] === '<') {
const verbatim = source.slice(2, -1);
if (verbatim === '!' || verbatim === '!!') {
onError(`Verbatim tags aren't resolved, so ${source} is invalid.`);
return null;
}
if (source[source.length - 1] !== '>')
onError('Verbatim tags must end with a >');
return verbatim;
}
const [, handle, suffix] = source.match(/^(.*!)([^!]*)$/s);
if (!suffix)
onError(`The ${source} tag has no suffix`);
const prefix = this.tags[handle];
if (prefix) {
try {
return prefix + decodeURIComponent(suffix);
}
catch (error) {
onError(String(error));
return null;
}
}
if (handle === '!')
return source; // local tag
onError(`Could not resolve tag: ${source}`);
return null;
}
/**
* Given a fully resolved tag, returns its printable string form,
* taking into account current tag prefixes and defaults.
*/
tagString(tag) {
for (const [handle, prefix] of Object.entries(this.tags)) {
if (tag.startsWith(prefix))
return handle + escapeTagName(tag.substring(prefix.length));
}
return tag[0] === '!' ? tag : `!<${tag}>`;
}
toString(doc) {
const lines = this.yaml.explicit
? [`%YAML ${this.yaml.version || '1.2'}`]
: [];
const tagEntries = Object.entries(this.tags);
let tagNames;
if (doc && tagEntries.length > 0 && identity.isNode(doc.contents)) {
const tags = {};
visit.visit(doc.contents, (_key, node) => {
if (identity.isNode(node) && node.tag)
tags[node.tag] = true;
});
tagNames = Object.keys(tags);
}
else
tagNames = [];
for (const [handle, prefix] of tagEntries) {
if (handle === '!!' && prefix === 'tag:yaml.org,2002:')
continue;
if (!doc || tagNames.some(tn => tn.startsWith(prefix)))
lines.push(`%TAG ${handle} ${prefix}`);
}
return lines.join('\n');
}
}
Directives.defaultYaml = { explicit: false, version: '1.2' };
Directives.defaultTags = { '!!': 'tag:yaml.org,2002:' };
exports.Directives = Directives;