2024 05 06 addressing typescript code issues with property setting importing files and typing - bizkite-co/handterm GitHub Wiki
original file name: Codeium Chat - TqfN3hlhd8Vt59cCAD5PlLdxGOpB3ZL0.md
summary: The conversation revolved around debugging issues related to TypeScript code. The user encountered errors while trying to set properties on undefined objects, import and parse HTML and JSON files, and strongly type JSON imports. Solutions and explanations were provided for each problem, such as verifying element existence before setting properties, using fetch
and DOMParser
for loading and parsing HTML files, handling JSON parsing in PowerShell, and handling JSON imports in TypeScript while considering browser MIME type restrictions and TypeScript configurations. The issue of importing an array from a JSON file with a different structure (array vs. single object) was also discussed, along with suggestions for defining types or interfaces to properly handle the data structure during import.
date: 2024-05-06T09:44
Note: This is purely the output of the chat conversation and does not contain any raw data, codebase snippets, etc. used to generate the output.
User at 9:44 am, May 6, 2024
I am getting this error in the browser dev tools:
HandChord.ts:41
Uncaught TypeError: Cannot set properties of undefined (setting 'checked')
at new HandChord (HandChord.ts:41:47)
at HTMLDocument.<anonymous> (chord-phrase.ts:4:23)
The line it points to is:
---
**Codeium** _at 9:44 am, May 6, 2024_
The error message you're encountering indicates that at `HandChord.ts:41`, there's an attempt to set a property `checked` on an object that is `undefined`. Without the full code, I can't be certain, but based on the previously shared context snippets, the likely culprit is this line in the `HandChord` constructor:
```typescript
this.voiceMode.checked = localStorage.getItem('voiceMode') == 'true';
If this.voiceMode
is undefined
, it means the document.getElementById("voiceMode")
did not find an element with the ID voiceMode
. Check to ensure the element with ID voiceMode
exists in the DOM at the time the HandChord
constructor is called. If the element is not present or the script is executed before the DOM is fully loaded, this could cause the error you're seeing.
Make sure that:
- The element with ID
voiceMode
exists in the HTML. - The script is included at the end of the body or you are waiting for the DOM to be fully loaded using
document.addEventListener("DOMContentLoaded", ...)
.
User at 10:17 am, May 6, 2024
Can I load and parse an HTML file into NextCharsDisplay.ts
? I want to load layouts/shortcodes/chord-list.html
and treat it like an object.
Codeium at 10:17 am, May 6, 2024
In a browser environment, you can fetch and parse an HTML file using the fetch
API and the DOMParser
API. Here's a basic example of how you could do that:
async function loadAndParseHTML(path: string): Promise<Document> {
const response = await fetch(path);
const htmlString = await response.text();
const parser = new DOMParser();
const doc = parser.parseFromString(htmlString, 'text/html');
return doc;
}
// Usage
loadAndParseHTML('/path/to/layouts/shortcodes/chord-list.html')
.then((doc) => {
// You can now treat 'doc' as a document object
const element = doc.querySelector('.some-selector');
// Do something with the element
})
.catch((error) => {
console.error('Error loading or parsing HTML:', error);
});
For NextCharsDisplay.ts
, integrate the above function where needed, making sure to replace '/path/to/layouts/shortcodes/chord-list.html'
with the correct path to your HTML file within your application.
Keep in mind that for security reasons, browsers restrict cross-origin HTTP requests initiated from within scripts, so the HTML file needs to be served from the same domain as your application, or the server must include the appropriate CORS headers.
User at 10:19 am, May 6, 2024
What if I wanted to use PowerShell to read that file and output a new JSON file from it?
Codeium at 10:20 am, May 6, 2024
To read an HTML file using PowerShell and output a new JSON file, you'll need to parse the HTML content and convert the desired data into a PowerShell object before exporting it to a JSON file.
PowerShell does not have a built-in HTML parser, but you can use regex for simple parsing or leverage the HtmlAgilityPack
library for more complex HTML parsing. Below is an example using a simple regex approach:
# Define the path to the HTML file
$htmlFilePath = "path\to\layouts\shortcodes\chord-list.html"
# Read the content of the HTML file
$htmlContent = Get-Content $htmlFilePath -Raw
# Use regex to extract data - this is a simplistic example and may need to be adapted
$matches = [regex]::Matches($htmlContent, '<div\s+class="(?<class>[^"]+)".*?>(?<content>.*?)</div>')
# Create an array to hold the parsed objects
$parsedObjects = @()
foreach ($match in $matches) {
$class = $match.Groups["class"].Value
$content = $match.Groups["content"].Value
# Create a custom object with the extracted data
$object = [PSCustomObject]@{
Class = $class
Content = $content
}
# Add the custom object to the array
$parsedObjects += $object
}
# Define the path for the new JSON file
$jsonFilePath = "path\to\output.json"
# Export the array of objects to a JSON file
$parsedObjects | ConvertTo-Json | Set-Content $jsonFilePath
Please note that regex is generally not recommended for parsing HTML, as HTML can be complex and not well-suited for regex patterns. If your HTML parsing needs are more complex, consider using the HtmlAgilityPack
library in a PowerShell script:
First, install the HtmlAgilityPack
NuGet package if you haven't already:
Install-Package HtmlAgilityPack -Scope CurrentUser
Then, you can use the library to parse HTML:
# Load the HtmlAgilityPack assembly
Add-Type -Path "path\to\HtmlAgilityPack.dll"
# Define the path to the HTML file
$htmlFilePath = "path\to\layouts\shortcodes\chord-list.html"
# Read the content of the HTML file
$htmlContent = Get-Content $htmlFilePath -Raw
# Create an HtmlDocument object and load the HTML content
$htmlDocument = New-Object HtmlAgilityPack.HtmlDocument
$htmlDocument.LoadHtml($htmlContent)
# Use HtmlAgilityPack to query the document
$nodes = $htmlDocument.DocumentNode.SelectNodes('//div[@class="some-class"]')
# Create an array to hold the parsed objects
$parsedObjects = @()
foreach ($node in $nodes) {
# Create a custom object with the extracted data
$object = [PSCustomObject]@{
Class = $node.GetAttributeValue("class", "")
Content = $node.InnerText
}
# Add the custom object to the array
$parsedObjects += $object
}
# Define the path for the new JSON file
$jsonFilePath = "path\to\output.json"
# Export the array of objects to a JSON file
$parsedObjects | ConvertTo-Json | Set-Content $jsonFilePath
Adjust the XPath queries and object properties according to the structure of your HTML and the data you need to extract.
User at 10:54 am, May 6, 2024
I've converted the data to JSON and now I am importing it with: import * as allChords from "../../static/js/chord-list.json"
How can I strongly typle the allChords
object?
Codeium at 10:55 am, May 6, 2024
To strongly type the allChords
object you've imported from JSON, you would first define an interface or type that represents the structure of the chords within the JSON file. Here's how you can do it:
First, determine the structure of your chord-list.json
. If it's an array of objects, each representing a chord, your interface might look something like this:
interface Chord {
id: string;
name: string;
// Add other properties relevant to your chord structure
}
Then, you can import the JSON and declare its type using the defined interface:
import * as allChordsData from "../../static/js/chord-list.json";
// Assuming allChordsData is an array of Chords
const allChords: Chord[] = allChordsData as unknown as Chord[];
In this example, the as unknown as Chord[]
is a type assertion that tells TypeScript to treat the imported data as an array of Chords. You need to use unknown
as an intermediate step because TypeScript doesn't allow direct type assertions from any
to a more specific type unless you use unknown
as a middle step.
However, if TypeScript is configured with the resolveJsonModule
option enabled, you can directly type the import without casting:
import { Chord } from "./path/to/chord-interface";
import allChordsData from "../../static/js/chord-list.json";
// This will already be typed if resolveJsonModule is enabled in tsconfig.json
const allChords: Chord[] = allChordsData;
Make sure your tsconfig.json
has the resolveJsonModule
option set to true
:
{
"compilerOptions": {
"resolveJsonModule": true,
// Other options...
}
}
With resolveJsonModule
enabled, TypeScript will infer the type of the imported JSON file based on its contents, and you can reference it with the expected type directly.
User at 11:26 am, May 6, 2024
I keep getting this error:
[1] Error: error building site: JSBUILD: failed to transform "ts/terminal/main.ts" (text/typescript): "D:\T3\Projects\self\handex.io\assets\ts\NextCharsDisplay.ts:6:27": Could not resolve "../../static/js/chord-list.json"
Codeium at 11:26 am, May 6, 2024
The error message suggests that the Hugo site's build process is failing to resolve the path to chord-list.json
during TypeScript transformation. This might be due to a number of reasons:
-
Incorrect Relative Path: The relative path mentioned in the import statement does not correctly point to the location of the
chord-list.json
file. Double-check the directory structure to ensure the path is correct. -
Hugo's JS Build Tool: Hugo uses its own build tool for processing JavaScript and TypeScript, which might not support the
resolveJsonModule
option that is typically available intsc
(the TypeScript compiler). Therefore, importing JSON files directly in TypeScript may not work out of the box with Hugo's build pipeline. -
Configuration Issue: There might be a configuration issue in the build tool that Hugo is using that prevents it from handling JSON imports.
To resolve this issue:
-
You can try to include the JSON data as a JavaScript module instead of a JSON file. Export the JSON object from a
.ts
file that is sure to be resolved by Hugo's build tool.// static/js/chord-list.ts export const allChords = [ // ... your chord objects ];
-
Then import it into your TypeScript file as:
// Use the .ts extension instead of .json import { allChords } from "../../static/js/chord-list";
-
If the above solution does not work, you might need to handle the JSON data outside of your TypeScript files, using Hugo's data template features or through other means of injecting the data into your scripts.
-
Lastly, ensure that any build or bundler configurations (like Webpack, if you're using it) are set up to handle JSON file imports.
If you can configure the underlying tool that Hugo uses for JS builds (such as esbuild, Webpack, etc.), you might be able to adjust the settings to resolve JSON modules. Otherwise, you'll need to adapt your approach to fit within Hugo's limitations.
User at 11:33 am, May 6, 2024
Ok, I moved it closer to avoid the Hugo mapping problem.
Now I am getting this error in the dev tools, but at least the site loads:
Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "application/json". Strict MIME type checking is enforced for module scripts per HTML spec.
Codeium at 11:33 am, May 6, 2024
This error occurs because modern browsers enforce strict MIME type checking for module scripts for security reasons. When you import a module using the import
statement, the browser expects a JavaScript module with a MIME type of text/javascript
or application/javascript
. Since you're trying to import a JSON file, which has a MIME type of application/json
, the browser refuses to execute it as a JavaScript module.
To resolve this, instead of directly importing the JSON file in your TypeScript file (which would cause the browser to try and load it as a module), you should load and parse the JSON file at runtime using the fetch
API. Here's an example of how you could do this:
// Assuming the JSON file is now in the 'static/js/' directory
const jsonPath = '/static/js/chord-list.json';
async function loadChords() {
try {
const response = await fetch(jsonPath);
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
const data = await response.json();
// Now you can use 'data' as a JavaScript object
console.log(data);
} catch (error) {
console.error('Error fetching chords:', error);
}
}
loadChords();
In this code, we use fetch
to load the JSON file and then parse it as JSON. The resulting object can be used in your script as needed. This also means you will not import the JSON file at the top of your script, as the data will be loaded asynchronously at runtime.
User at 11:37 am, May 6, 2024
I don't seem to have that problem when I am loading this:
import * as phrases from '../phrases.json';
in the XtermAdapter.ts
. Can I modify the data to simplify the import?
Codeium at 11:37 am, May 6, 2024
If importing JSON like import * as phrases from '../phrases.json';
is working without issues in XtermAdapter.ts
, it's likely that your TypeScript configuration (or the build tool used by Hugo) supports JSON imports.
In this case, to simplify the import and avoid the MIME type error for chord-list.json
, you need to ensure that the file is placed in a location that is consistent with how phrases.json
is being served and imported. Here's what you can do:
-
Place the
chord-list.json
in the same directory asphrases.json
. Since you're able to importphrases.json
without any problems, placingchord-list.json
in the same directory and importing it in a similar manner should work. -
Ensure the file extension is
.json
. File extensions are important for build tools and servers to set the correct MIME type. -
Check for consistency in the TypeScript configuration. Ensure that the
tsconfig.json
file is configured correctly and consistently for both files. It should have theresolveJsonModule
andesModuleInterop
options set totrue
:
{
"compilerOptions": {
"resolveJsonModule": true,
"esModuleInterop": true,
// Other options...
}
}
- Simplify the import statement. If the JSON file is now in the same directory, you can import it as follows:
import * as allChords from './chord-list.json';
- Type the imported JSON data. Create a TypeScript type or interface that describes the structure of your JSON data:
interface Chord {
// Define the properties of each chord
id: string;
name: string;
// other properties...
}
// Assuming the JSON data is an array of chords
import allChordsData from './chord-list.json';
const allChords: Chord[] = allChordsData as unknown as Chord[];
By following these steps, you should be able to import chord-list.json
in a similar way to phrases.json
without encountering the MIME type error. If you still face issues, it could be due to the server configuration or the build process. Make sure the server is configured to serve .json
files correctly, and the build process includes the JSON files in the output directory.
User at 12:39 pm, May 6, 2024
It is loading the phrases.json
without error, but that is a single object of name-value pairs, whereas the chord-list.json
is an array.
Codeium at 12:40 pm, May 6, 2024
The difference in the structure of the JSON files might be affecting how they're treated by the TypeScript compiler or the build tool. TypeScript should be able to handle both objects and arrays in JSON modules, provided that the resolveJsonModule
option is enabled in your tsconfig.json
.
To import an array from a JSON file and ensure it's strongly typed, you would define a type or interface for the array items and then use that type when importing the JSON array. Here's an example of how you might do it:
First, define the type for the items in the array:
// Define the type for a single chord
interface Chord {
key: string;
chordCode: string;
index: number;
}
Then, import the JSON array and assert its type:
// Import the JSON array
import chordsData from './chord-list.json';
// Assert the type of the imported data
const allChords: Chord[] = chordsData as Chord[];
The resolveJsonModule
option in tsconfig.json
will ensure that TypeScript treats the imported JSON as an array of objects matching the Chord
interface. Here's what your tsconfig.json
should include:
{
"compilerOptions": {
"resolveJsonModule": true,
"esModuleInterop": true,
// Other options...
}
}
If you have done this and it's still not working, you may need to check the build tool or server configuration. The error you mentioned earlier regarding MIME type is a runtime error that happens in the browser when it receives a JSON file with a module import statement. This should not happen if the TypeScript compiler is correctly transforming the imports during build time.
If you are still encountering issues, consider the following:
- Ensure the JSON file is being correctly copied to the output directory during the build process.
- Verify that any build tools (like Webpack, Rollup, or the one integrated with Hugo) are correctly configured to handle JSON imports.
- Check that your server is configured to serve JSON files with the correct MIME type (
application/json
) when not importing them as modules, but just fetching them viafetch
.
If none of these solutions work, you might consider converting your JSON array to a JSON object with a single property that is an array, to match the structure of phrases.json
. However, that should not be necessary if TypeScript and the build tool are configured correctly.
User at 12:42 pm, May 6, 2024
i have this in the NextCharsDisplay
:
import * as phrases from './phrases.json';
import allChordsData from './chord-list.json';
interface Chord {
key: string;
chordCode: string;
index: number;
}
const allChords: Chord[] = allChordsData as unknown as Chord[];
and I have:
"resolveJsonModule": true, /* Enable importing .json files. */
"esModuleInterop": true, /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
in the tsconfig.json
Codeium at 12:42 pm, May 6, 2024
Based on the provided information, your TypeScript configuration and imports look correct. The resolveJsonModule
option allows for importing .json
files, and esModuleInterop
enables a more lenient module format that can interoperate with CommonJS modules.
Since the TypeScript configuration and the code appear to be correct, there are a few additional steps to consider:
-
Check for Typos or Path Issues: Ensure there are no typos in the file names or the paths. Also, make sure that both
phrases.json
andchord-list.json
are in the same directory asNextCharsDisplay.ts
. -
Verify JSON Structure: Ensure that the structure of
chord-list.json
matches theChord[]
type. The JSON file should be an array of objects, each withkey
,chordCode
, andindex
properties. -
Check Build Process: Confirm that the build process used by Hugo for TypeScript files is not interfering with the import of JSON files. If Hugo's build process is causing the issue, you may need to adjust its configuration or use a custom build step for TypeScript files.
-
Explore Server Configuration: If the issue is occurring at runtime in the browser (and not during the build process), check your server's configuration to ensure that it serves JSON files with the correct
Content-Type
header (application/json
). -
Check for Caching Issues: Clear your browser cache and the cache of any build tools you're using to make sure you're not seeing an outdated error message.
-
Debug the Import: Try importing a different JSON file in the same way to see if the issue is with
chord-list.json
specifically or with JSON imports in general. -
Review Error Messages: Look at the complete error message and stack trace to see if there are additional clues about what might be going wrong.
If you have confirmed all of the above and the issue persists, please provide additional context or error messages that may be displayed during the build process or in the browser's console. This information can help in diagnosing the problem further.
User at 1:00 pm, May 6, 2024
None of that worked. I decided to export it like this as a workaround:
export const allChords = [
{
"key": "a",
"chordCode": "4",
"index": 0
},
Codeium at 1:01 pm, May 6, 2024
Exporting the array directly from a TypeScript file as you've done is indeed a valid workaround that avoids the issues with JSON imports altogether. This way, TypeScript will naturally handle the data as part of the compilation process without any additional configuration or potential runtime issues related to MIME types.
Just remember to define your Chord
interface as before and use it to type the allChords
array:
interface Chord {
key: string;
chordCode: string;
index: number;
}
export const allChords: Chord[] = [
{
"key": "a",
"chordCode": "4",
"index": 0
},
// ... other chords
];
This approach ensures that allChords
has the strong typing you wanted and can be safely used throughout your application.
Now, you can simply import allChords
wherever needed in your TypeScript files:
import { allChords } from './path-to-allChords';
// Use allChords in your code
This should work without any issues since it's a standard TypeScript import of typed data.