@ackplus/nest-dynamic-templates/dist/lib/errors/diagnose.js

A powerful and flexible dynamic template rendering library for NestJS applications with support for Nunjucks, Handlebars, EJS, Pug, MJML, Markdown, and more.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.diagnoseRenderError = diagnoseRenderError;
const template_errors_1 = require("./template.errors");
function diagnoseRenderError(cause, source, context, meta) {
    const err = toError(cause);
    const contextKeys = context ? Object.keys(context) : [];
    const location = extractLocation(err.message, meta);
    const missingVariable = extractMissingVariable(err.message, source, location);
    const snippet = location ? lineAt(source, location.line) : undefined;
    const reason = missingVariable
        ? `variable "${missingVariable}" is undefined`
        : cleanMessage(err.message);
    const subject = meta.templateName ? `template "${meta.templateName}"` : 'inline content';
    const tags = [
        [meta.engine, meta.language].filter(Boolean).join(' → '),
        meta.scope && `scope=${meta.scope}`,
        meta.locale && `locale=${meta.locale}`,
    ].filter(Boolean);
    const where = tags.length ? ` [${tags.join(', ')}]` : '';
    const message = `Failed to render ${subject}${where}: ${stripTrailingDot(reason)}.`;
    const hint = missingVariable
        ? buildMissingVarHint(missingVariable, contextKeys)
        : stageHint(meta.stage, meta.engine, meta.language);
    return new template_errors_1.TemplateRenderError({
        message,
        stage: meta.stage,
        engine: meta.engine,
        language: meta.language,
        templateName: meta.templateName,
        scope: meta.scope,
        scopeId: meta.scopeId,
        locale: meta.locale,
        missingVariable,
        contextKeys,
        location,
        snippet,
        hint,
    }, err);
}
function buildMissingVarHint(variable, contextKeys) {
    const provided = contextKeys.length
        ? `The render context has: [${contextKeys.join(', ')}].`
        : `The render context was empty.`;
    return `Pass "${variable}" in the render context. ${provided} To make it optional, guard it in the template, e.g. {{ ${variable} or "" }}.`;
}
function stageHint(stage, engine, language) {
    switch (stage) {
        case 'template-engine':
            return `Check the ${engine ?? 'template'} syntax and that every referenced variable is provided.`;
        case 'language-engine':
            return `Check that the content is valid ${language ?? 'markup'} after variable interpolation.`;
        case 'layout':
            return `The error happened while rendering the layout wrapper around this template.`;
        case 'subject':
            return `The error happened while rendering the subject line.`;
        default:
            return undefined;
    }
}
function toError(cause) {
    if (cause instanceof Error)
        return cause;
    if (typeof cause === 'string')
        return new Error(cause);
    try {
        return new Error(JSON.stringify(cause));
    }
    catch {
        return new Error(String(cause));
    }
}
function extractLocation(message, meta) {
    const patterns = [
        /\[Line (\d+),\s*Column (\d+)\]/i,
        /Parse error on line (\d+)/i,
        /(?:ejs|pug):(\d+)/i,
        />>\s*(\d+)\s*\|/,
        /\bon line (\d+)(?::(\d+))?/i,
        /\bline (\d+)(?::(\d+))?/i,
    ];
    for (const re of patterns) {
        const m = message.match(re);
        if (m) {
            const line = Number(m[1]);
            const column = m[2] !== undefined ? Number(m[2]) : undefined;
            if (Number.isFinite(line) && line > 0) {
                return column !== undefined && Number.isFinite(column)
                    ? { line, column }
                    : { line };
            }
        }
    }
    return undefined;
}
function extractMissingVariable(message, source, location) {
    const refError = message.match(/(\b[\w$][\w.$]*) is not defined/);
    if (refError)
        return refError[1];
    const njkCall = message.match(/Unable to call `?([\w.$]+)`?, which is undefined/i);
    if (njkCall)
        return njkCall[1];
    if (/attempted to output null or undefined value/i.test(message) && location) {
        return expressionAt(source, location);
    }
    return undefined;
}
const TOKEN_RE = /\{\{-?\s*([\s\S]*?)\s*-?\}\}|<%[=\-_]?\s*([\s\S]*?)\s*[-_]?%>|#\{\s*([\s\S]*?)\s*\}/g;
function expressionAt(source, location) {
    const lineText = rawLineAt(source, location.line);
    if (!lineText)
        return undefined;
    const tokens = [];
    TOKEN_RE.lastIndex = 0;
    let m;
    while ((m = TOKEN_RE.exec(lineText)) !== null) {
        const expr = (m[1] ?? m[2] ?? m[3] ?? '').trim();
        if (expr)
            tokens.push({ start: m.index, expr });
    }
    if (tokens.length === 0)
        return undefined;
    let chosen = tokens[0];
    if (location.column !== undefined) {
        const col = location.column;
        for (const t of tokens) {
            if (t.start <= col)
                chosen = t;
        }
    }
    return leadingVariable(chosen.expr);
}
function leadingVariable(expr) {
    const beforeFilter = expr.split('|')[0].trim();
    const path = beforeFilter.match(/^[\w$][\w.$]*(?:\[[^\]]+\])*/);
    return path ? path[0] : undefined;
}
function lineAt(source, line) {
    const raw = rawLineAt(source, line);
    if (raw === undefined)
        return undefined;
    const trimmed = raw.trim();
    return trimmed.length > 200 ? `${trimmed.slice(0, 197)}...` : trimmed;
}
function rawLineAt(source, line) {
    if (!source)
        return undefined;
    const lines = source.split(/\r?\n/);
    return lines[line - 1];
}
function cleanMessage(message) {
    return message
        .replace(/^Error:\s*/i, '')
        .replace(/\(unknown path\)\s*/gi, '')
        .replace(/\[Line \d+,\s*Column \d+\]\s*/gi, '')
        .replace(/\s+/g, ' ')
        .trim();
}
function stripTrailingDot(s) {
    return s.replace(/\.+$/, '');
}
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