* remove fetch_source_file_and_maybe_compile_async and
replace it with State.fetch_compiled_module
* remove SourceFile.js_source()
* introduce CompiledModule which is basically the same as
deno::SourceInfo and represents arbitrary file that has been
compiled to JS module
* introduce //cli/compilers module containing all compilers
* introduce JsCompiler which is a no-op compiler
- output is the same as input, no compilation takes place
- it is used for MediaType::JavaScript and MediaType::Unknown
* introduce JsonCompiler that wraps JSON in default export
* support JS-to-JS compilation using checkJs
* rename `ModuleMetaData` to `SourceFile` and remove TS specific
functionality
* add `TsCompiler` struct encapsulating processing of TypeScript files
* move `SourceMapGetter` trait implementation to `//cli/compiler.rs`
* add low-level `DiskCache` API for general purpose caches and use it in
`DenoDir` and `TsCompiler` for filesystem access
* don't use hash-like filenames for compiled modules, instead use
metadata file for storing compilation hash
* add `SourceFileCache` for in-process caching of loaded files for fast
subsequent access
* define `SourceFileFetcher` trait encapsulating loading of local and
remote files and implement it for `DenoDir`
* define `use_cache` and `no_fetch` flags on `DenoDir` instead of using
in fetch methods
The rules are now as follows:
* In `import` statements, as mandated by the WHATWG specification,
the import specifier is always treated as a URL.
If it is a relative URL, it must start with either / or ./ or ../
* A script name passed to deno as a command line argument may be either
an absolute URL or a local path.
- If the name starts with a valid URI scheme followed by a colon, e.g.
'http:', 'https:', 'file:', 'foo+bar:', it always interpreted as a
URL (even if Deno doesn't support the indicated protocol).
- Otherwise, the script name is interpreted as a local path. The local
path may be relative, and operating system semantics determine how
it is resolved. Prefixing a relative path with ./ is not required.
* Compiler no longer has its own Tokio runtime. Compiler handles one
message and then exits.
* Uses the simpler ts.CompilerHost interface instead of
ts.LanguageServiceHost.
* avoids recompiling the same module by introducing a hacky but simple
`hashset<string>` that stores the module names that have been already
compiled.
* Removes the CompilerConfig op.
* Removes a lot of the mocking stuff in compiler.ts like `this._ts`. It
is not useful as we don't even have tests.
* Turns off checkJs because it causes fmt_test to die with OOM.
Removed `extmap` and added .mjs entry in `map_file_extension`.
The assert in the compiler does not need to be updated, since it is
resolving from the compiled cache instead of elsewhere (notice the .map
is asserted next to it)
