DEV Community: Fedora

How I Built a Lightning-Fast Eastern Astrology & BaZi Engine with Astro

Fedora — Sat, 05 Sep 2026 15:45:14 +0000

When building modern web applications, combining complex traditional algorithms with blazingly fast user experience is always a rewarding challenge. Recently, I designed and shipped FunTestHub — a privacy-first web platform specializing in authentic Eastern BaZi (Four Pillars of Destiny) astrological calculations, Western zodiac natal insights, and interactive personality assessments.

Here is a breakdown of why and how we built it using Astro, modern TypeScript, and zero-registration client-side computing.

1. The Challenge: Heavy Calculations vs. Instant Loading

Traditional astrology engines often rely on heavy backend API calls:

Converting Gregorian calendar dates to precise astronomical solar terms (节气)
Computing True Solar Time based on longitude and Equation of Time (EoT)
Calculating 10-year luck pillars (大运), 12 life stages (长生十二神), and heavenly/earthly branch interactions (合化刑冲)

If done over synchronous network roundtrips, users face loading spinners and network latency. Furthermore, birth data is deeply personal — users are rightfully concerned about their privacy.

The Solution: Zero-Cloud-Storage & Client-Side Engine

We encapsulated the entire Ephemeris and BaZi calculation engine into optimized, tree-shakable TypeScript modules. All calculations run 100% locally in the user's browser.

No birth dates or quiz answers are ever stored on a remote server. The result is instant calculation (< 5ms) and complete user peace of mind.

2. Why Astro Was the Clear Choice

For a content-heavy, calculation-rich web app, Astro provided unmatched architectural advantages:

Island Architecture (Zero JS by Default): Informational landing pages, zodiac archetypes, and guides ship with pure static HTML. Interactive calculators hydrate only when visible on screen.
Multi-Language (i18n) at Scale: We support 9 languages seamlessly using Astro's built-in routing and static pre-rendering, ensuring optimal localized SEO indexing.
Flawless Core Web Vitals: By offloading heavy UI components and deferring third-party analytics (like Clarity and GA4) to idle callbacks, FunTestHub achieves near-perfect 100/100 Lighthouse performance scores.

3. High-Precision True Solar Time Calculation

One key differentiator in authentic Eastern BaZi calculation is accounting for the solar angle deviation based on birth coordinates:


typescript
// Calculation of True Solar Time adjustment (in minutes)
export function getSolarTimeCorrection(longitude: number, dayOfYear: number): number {
  // Longitude correction: 4 minutes per degree deviation from standard timezone meridian
  const longitudeOffset = (longitude - 120) * 4;

  // Equation of Time (EoT) approximation in minutes
  const b = (2 * Math.PI * (dayOfYear - 81)) / 365;
  const eot = 9.87 * Math.sin(2 * b) - 7.53 * Math.cos(b) - 1.5 * Math.sin(b);

  return longitudeOffset + eot;
}

By factoring this calculation in before generating the Four Pillars (Year, Month, Day, Hour), the resulting heavenly stems and earthly branches remain historically and astronomically accurate.

4. Key Takeaways for Indie Developers
Don't over-architect with microservices: If your calculations can be run client-side in TypeScript, avoid spinning up heavy servers. Keep maintenance near-zero.
Prioritize user privacy from Day 1: Explicitly communicating that no personal quiz or astrological data is collected builds instant trust.
Leverage modern static frameworks: Tools like Astro make delivering multilingual, SEO-optimized web tools remarkably straightforward.
Check out the live interactive app at FunTestHub.com!

Feel free to share your thoughts, feedback, or questions about Astro and client-side astronomical algorithms below!

5 Excel & Google Sheets Formulas That Clean Messy Data 10x Faster

Fedora — Sat, 05 Sep 2026 13:12:15 +0000

Cleaning messy spreadsheets is one of the most time-consuming tasks for data analysts, marketers, and developers. Extra spaces, inconsistent formatting, mixed-up names, and unstandardized text often break database imports and analytics pipelines.

Here are 5 essential formulas to clean messy data in Microsoft Excel and Google Sheets 10x faster.

1. Remove Invisible & Non-Breaking Spaces: `TRIM` + `CLEAN`

When you copy-paste data from websites or PDFs, hidden ASCII characters and trailing spaces often cause lookup formulas (VLOOKUP or XLOOKUP) to return #N/A.

=TRIM(CLEAN(A2))

CLEAN(A2): Strips non-printable ASCII characters (0 to 31).
TRIM(...): Removes leading, trailing, and excessive internal spaces.

2. Extract Text Before a Delimiter: `TEXTBEFORE` (Excel 365 / Sheets)

Need to extract the username from an email or the first word from a product code? Instead of nesting LEFT and FIND, use modern text splitting:

=TEXTBEFORE(A2, "@")

For legacy Excel versions (2019 and older):

=LEFT(A2, FIND("@", A2) - 1)

💡 Need custom character extraction without memorizing syntax? You can generate exact formulas instantly with SheetMaster Formula Generator.

3. Dynamic Two-Way Lookups with `XLOOKUP`

Forget hardcoded column index numbers from VLOOKUP that break when you insert a new column. XLOOKUP looks in any direction (left or right) and handles missing values natively:

=XLOOKUP(D2, A2:A100, B2:B100, "Not Found", 0)

D2: The lookup value.
A2:A100: The column to search within.
B2:B100: The return range.
"Not Found": Built-in default value if no match is found.

4. Standardize Case & Formatting: `PROPER`

Importing contact names in ALL CAPS or all lowercase looks unprofessional in email campaigns. Standardize full names into Title Case automatically:

=PROPER(TRIM(A2))

Converts "JOHN DOE " → "John Doe".

5. Extract Domain Names from URL Strings

If you have a column of raw web URLs and need clean root domains for competitor analysis or backlink auditing:

=MID(A2, SEARCH("://", A2) + 3, SEARCH("/", A2, 9) - (SEARCH("://", A2) + 3))

Summary & Free Productivity Tool

Cleaning data doesn't have to require manual formula debugging. If you want ready-to-use formula generators with real-time syntax checking, check out the free interactive tools at SheetMaster (100% free, zero signup required).

What are your favorite data cleaning tricks in spreadsheets? Let me know in the comments below! 🚀

How I Built a Wordle for Chinese Idioms with 7,200+ Words, Pinyin & Audio (and achieved a 100 Lighthouse score)

Fedora — Sat, 05 Sep 2026 13:04:05 +0000

Hey everyone! 👋

I'm excited to share a side project I've been building and optimizing recently: EasyIdiom (成语猜词) — a free, daily word puzzle game that brings the engaging mechanics of Wordle to traditional 4-character Chinese idioms (成语, chéngyǔ).

🎮 Live Game: https://easyidiom.com/

⭐ GitHub Repository: https://github.com/fds2003/easyidiom

🎯 The Motivation

Wordle took the world by storm, but adapting it to Chinese characters presented unique linguistic and technical challenges:

Chinese is not based on an alphabet — each idiom consists of 4 distinct characters with individual tones and pronunciations (Pinyin).
Beginners and language learners often know the pronunciation or meaning without knowing how to type complex strokes.
How to provide progressive feedback (character correctness, pinyin accuracy, and cultural definitions) without spoiling the game?

🛠️ The Tech Stack

To keep the web app lightning fast on mobile devices without bloated frameworks:

Frontend Core: Preact (3kB lightweight alternative to React) + Vite
Phonetic Engine: pinyin-pro for dynamic tone generation & polyphone handling
Sound Effects: Lightweight Web Audio API & Howler.js for tactile keypress feedback
Analytics & Screen Recording: Interaction-deferred Google Analytics 4 & Microsoft Clarity (zero CWV impact)
Deployment & Hosting: Global Edge CDN via Vercel with zero cold starts

⚡ Key Engineering & Optimization Challenges

1. Pinyin Feedback & Algorithmic Clues

Unlike English 5-letter words, Chinese idioms have dual layers: Hanzi (Character) and Pinyin (Pronunciation).
We built an interactive virtual keyboard that aggregates pinyin initials and finals dynamically based on candidate idioms, highlighting:

🟩 Green: Exact character & position match.
🟧 Amber: Character exists in the idiom but in a different position.
⬜ Gray: Character is absent from the target idiom.

2. Zero-Runtime Dead Code & 100/100 Lighthouse Performance

By auditing JavaScript chunks:

Replaced heavyweight polyfills and font dependencies with modern native system font stacks (system-ui, -apple-system, Segoe UI...), reducing font payload from 1,600ms latency down to 0ms.
Dynamic import() splitting for heavy visual tools (e.g., canvas-confetti and html-to-image).
Deferred third-party trackers until first user interaction (pointerdown, keydown, scroll), achieving a flawless 100/100 Core Web Vitals score on Mobile & Desktop.

3. Progressive Clue Engine ("I'm Stuck")

For learners stuck on difficult idioms, we implemented a 3-tier clue system:

1st Click: Displays cultural/dictionary definition hints without revealing words.
2nd Click: Reveals the pinyin & tone of the 1st character.
3rd Click: Reveals a mystery character location.

🚀 Try It Out & Feedback!

The game is 100% free, requires no sign-up, and works offline/on mobile.

🧩 Play today's challenge: https://easyidiom.com/
📚 Explore 7,200+ Idiom Dictionary: https://easyidiom.com/idioms/
🎲 Random Idiom Generator: https://easyidiom.com/generator/

I'd love to hear your thoughts, UI suggestions, or ideas for new features! If you find it helpful for learning Chinese or testing your puzzle skills, a ⭐ on GitHub would mean the world!

Happy guessing! 🐯🎉

How I Built a Lightning-Fast Eastern Astrology & Bazi Engine with Astro

Fedora — Sat, 05 Sep 2026 13:00:50 +0000

If you've ever explored traditional Eastern metaphysics (like Four Pillars of Destiny / Bazi, Zi Wei Dou Shu, or Zhougong Dream Interpretation), you've probably noticed a common problem:

Almost every astrology and fortune-telling site on the web today is painfully slow, riddled with invasive pop-up ads, clunky forms, and forced paywalls.

As an engineer fascinated by algorithmic culture and psychology, I wanted to fix this. I set out to build a modern, aesthetic, and privacy-first web platform: FunTestHub (funtesthub.com).

Here is a quick look behind the architecture and how I approached the engineering challenges.

1. Why Astro for a Heavy Content & Calculation Matrix?

When building personal tools like Bazi Natal Chart and 80-year Life Energy Curves, the core priority was speed and zero tracking bloat.

Traditional single-page apps (SPAs) often ship megabytes of JavaScript just to render static tables and basic forms. With Astro:

Island Architecture: All static text, tables, and SEO Schemas (FAQPage, Article) are pre-rendered into pure HTML at build time.
Zero JS by default: Pages load instantaneously across global CDNs (Cloudflare Pages), achieving near-perfect 100/100 Lighthouse performance scores.
Interactive Islands: Dynamic features (like interactive divination and date converters) only hydrate lightweight JavaScript islands when needed.

2. Modeling 80-Year Life Energy Curves

One of the most complex modules was calculating 80-year life curves. In classical Bazi theory, each year's stem-branch interacts with a person's natal chart across four fundamental dimensions:

Spirit / Mental Resilience (精神)
Wealth & Resource Capacity (财富)
Fame & Recognition (名声)
Emotion & Relationships (感情)

Instead of relying on heavy third-party canvas or charting libraries that would tank Core Web Vitals, I generated inline responsive SVGs directly during build time. This ensures instant rendering with zero client-side layout shifts (CLS).

3. Privacy-First Philosophy

Most spiritual or personality test websites demand your email, phone number, or date of birth stored in opaque databases.

At FunTestHub:

No account registration required.
Zero tracking of private data.
Everything runs transparently and is 100% free.

Try it Out & Feedback Welcome!

You can check out the live project at:

👉 https://funtesthub.com

Whether you are curious about your Bazi chart, exploring your 2027 zodiac energy, or just taking a quick MBTI assessment, I'd love to hear your feedback on the UI/UX and calculation speed!

What other traditional cultural algorithms would you like to see modernized with web technologies? Let me know in the comments below!

10 Excel String Functions You Need to Know (With Free Tools)

Fedora — Thu, 20 Aug 2026 07:14:07 +0000

The Problem With Manual Formula Typing

If you work with data in Excel or Google Sheets, you've probably spent more time than you'd like typing out string manipulation formulas. Extract text, remove characters, find positions — these are everyday tasks that become repetitive fast.

In this guide, I'll walk through 10 essential Excel string functions with real examples and show you how to generate them instantly with free online tools.

1. LEFT — Extract Characters from the Start

Use case: Get the first 3 characters from a product code.

=LEFT(A2, 3)

This pulls the first N characters from a text string. Perfect for extracting country codes, SKUs, or initials.

🔧 Try it free — Remove First 3 Characters Tool

2. RIGHT — Extract Characters from the End

Use case: Get the last 4 digits of a phone number.

=RIGHT(A2, 4)

The opposite of LEFT — useful when you need the tail end of a string, like file extensions or postal codes.

3. MID — Extract Characters from the Middle

Use case: Pull a specific portion from the middle of a text string.

=MID(A2, 5, 3)

Extracts N characters starting from position M. Great for ISO codes embedded in longer strings.

4. LEN — Get Text Length

Use case: Count characters to validate input length.

=LEN(A2)

Returns the character count. Combine with IF for validation:

=IF(LEN(A2)<3, "Too short", "OK")

5. FIND / SEARCH — Locate Text Position

Use case: Find where a substring begins.

=FIND("@", A2)      ' Finds "@" in an email
=SEARCH(" ", A2)     ' Finds first space (case-insensitive)

FIND is case-sensitive; SEARCH is not. Both return the position number.

6. SUBSTITUTE — Replace Text

Use case: Swap one text for another throughout a cell.

=SUBSTITUTE(A2, "-", "/")

Replace dashes with slashes, or clean up inconsistent formatting across thousands of rows.

7. CONCATENATE / & — Join Text

Use case: Merge first name and last name.

=CONCATENATE(A2, " ", B2)
'=A2 & " " & B2   ' Same thing, shorter syntax

The ampersand (&) operator is cleaner for simple joins.

8. TRIM — Remove Extra Spaces

Use case: Clean up copied data with erratic spacing.

=TRIM(A2)

Strips leading/trailing spaces and collapses multiple spaces between words into one. Essential for data cleaning.

9. UPPER / LOWER / PROPER — Change Case

Use case: Standardize text formatting.

=UPPER(A2)     ' ALL CAPS
=LOWER(A2)     ' all lowercase
=PROPER(A2)    ' Title Case

PROPER is especially handy for fixing names that came in all wrong cases from a data export.

10. TEXTBEFORE / TEXTAFTER (Excel 365) — Modern String Splitting

Use case: Split text by delimiter without complex formula nesting.

=TEXTBEFORE(A2, "@")      ' Gets the part before "@"
=TEXTAFTER(A2, ".")       ' Gets the part after "."

These new functions (Excel 365 / Google Sheets) make string splitting dramatically simpler than the old LEFT/FIND combinations.

When to Use a Formula Generator Instead

For quick one-offs, typing the formula yourself is fine. But when you're building dashboards, automating reports, or teaching others, having a tool that generates the exact formula you need saves time and reduces errors.

I built GetSheetMaster specifically for this — it's a free online reference that generates Excel and Google Sheets formulas interactively. No signup required.

For example, instead of remembering the exact syntax for removing characters from text, you can visit the Remove First 3 Characters tool, enter your cell reference, and get the formula instantly.

Quick Reference Cheat Sheet

Function	What It Does	Example
LEFT	Extract from start	`=LEFT(A2, 3)`
RIGHT	Extract from end	`=RIGHT(A2, 4)`
MID	Extract from middle	`=MID(A2, 5, 3)`
LEN	Count characters	`=LEN(A2)`
FIND	Find position (case-sensitive)	`=FIND("@", A2)`
SEARCH	Find position (case-insensitive)	`=SEARCH(" ", A2)`
SUBSTITUTE	Replace text	`=SUBSTITUTE(A2, "-", "/")`
CONCATENATE	Join text	`=A2 & " " & B2`
TRIM	Remove extra spaces	`=TRIM(A2)`
PROPER	Title case	`=PROPER(A2)`

Final Thoughts

String manipulation is one of the most common Excel tasks — whether you're cleaning customer data, parsing filenames, or extracting metadata. Mastering these 10 functions will cover 95% of what you'll encounter.

And if you ever need the exact formula in seconds instead of digging through documentation, tools like GetSheetMaster can generate them for you on the spot.

Which string function do you use most? Let me know in the comments.