fix(plugin): handle decorators with property access expressions in getIdentifierFromName

[jorenl]

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PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

When the plugin inspects decorators that use a property access expression, such as with a namespace import in the below example, the getIdentifierFromName() utility function throws and the decorator is not handled.

import * as class_validator from "class-validator"

class TestDto {
  @class_validator.IsIn(["red", "green", "blue"])
  color: string;
}

Issue Number: N/A

What is the new behavior?

The decorator name identifier is returned, IsIn in the above example, and the decorator is handled.

Does this PR introduce a breaking change?

• Yes
• No

Other information

Since getNameFromExpression right below has explicit support for property access expressions, I believe this is was a simple typo. (checking expression instead of identifier return by getNameFromExpression, which is then returned).

I ran into this issue while developing a different NestJS CLI plugin, which I want to run before the @nestjs/swagger one, which is generating class-validator and class-transformer decorators based on typescript types. Without using namespace imports, typescript strips the necessary import declarations when emitting, which I believe is why this plugin uses the same technique in abstract.visitor.ts.

This is my first PR in this repo, so if I'm not following correct patterns, let me know and I'll happily adjust.