fix(model): don't require TimelineComponent for media-only option. close #21686

[MohammadWasi]

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

Stops ECharts from wrongly requiring TimelineComponent when an option uses the { baseOption, media } form without a timeline.

Fixed issues

• [Bug] baseOption with media incorrectly requires TimelineComponent when no timeline is configured #21686: baseOption with media incorrectly requires TimelineComponent when no timeline is configured

Details

Before: What was the problem?

Using the modular build without registering TimelineComponent, an option structured with baseOption + media but no timeline reported:

Component timeline is used but not imported.
import { TimelineComponent } from 'echarts/components';
echarts.use([TimelineComponent]);

Depending on the environment this surfaces as an exception during setOption, forcing users to register a component they don't use.

Root cause: in OptionManager.parseRawOption, when a baseOption is declared, the parser injects the root timeline into it for merge purposes:

if (!baseOption.timeline) {
    baseOption.timeline = timelineOnRoot; // `undefined` when no timeline is configured
}

This leaves an own timeline key on baseOption whose value is undefined. checkMissingComponents then iterates every key of the option and reports any mainType whose class isn't registered — so the empty timeline entry is wrongly flagged as a missing TimelineComponent. It only reproduces with the { baseOption, media } form because the plain root-option path doesn't inject that key.

After: How does it behave after the fixing?

checkMissingComponents now skips component options whose value is null/undefined, since such an entry means the component isn't actually used. An option with baseOption + media and no timeline works with the modular build without registering TimelineComponent. Genuine missing-component reporting is unchanged (a real timeline: {...} still reports when unregistered).

each(option, function (componentOption, mainType) {
    // A `null`/`undefined` option value means the component is not actually used.
    if (componentOption != null && !ComponentModel.hasClass(mainType)) {
        // ...report as missing...
    }
});

The fix is guarded by __DEV__ (this check only runs in development builds), so there is no production behavior change.

Regression test

Added a case to test/ut/spec/model/componentMissing.test.ts asserting that a { baseOption, media } option without a timeline does not report TimelineComponent as missing. Verified it fails on master (reproduces the bug) and passes with this fix. The full test/ut/spec/model suite passes, along with npm run lint and npm run checktype.

Document Info

One of the following should be checked.

• This PR doesn't relate to document changes
• The document should be updated later
• The document changes have been made in apache/echarts-doc#xxx

Misc

Security Checking

• This PR uses security-sensitive Web APIs.

ZRender Changes

• This PR depends on ZRender changes (ecomfe/zrender#xxx).

Related test cases or examples to use the new APIs

Added a Jest regression test in test/ut/spec/model/componentMissing.test.ts.

[echarts-bot]

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