[minor] Adds some docs to the LSP interface

src/harness/harnessLanguageService.ts

@@ -520,7 +520,6 @@ namespace Harness.LanguageService {
         getNavigationTree(fileName: string): ts.NavigationTree {
             return unwrapJSONCallResult(this.shim.getNavigationTree(fileName));
         }
-
         getOutliningSpans(fileName: string): ts.OutliningSpan[] {
             return unwrapJSONCallResult(this.shim.getOutliningSpans(fileName));
         }

src/services/types.ts

@@ -289,43 +289,110 @@ namespace ts {
     // with a language service host instance
     //
     export interface LanguageService {
+        /** This is used as a part of restarting the language service. */
         cleanupSemanticCache(): void;
 
+        /**
+         * Gets errors indicating invalid syntax in a file.
+         *
+         * In English, "this cdeo have, erorrs" is syntactically invalid because it has typos,
+         * grammatical errors, and misplaced punctuation. Likewise, examples of syntax
+         * errors in TypeScript are missing parentheses in an `if` statement, mismatched
+         * curly braces, and using a reserved keyword as a variable name.
+         *
+         * These diagnostics are inexpensive to compute and don't require knowledge of
+         * other files. Note that a non-empty result increases the likelihood of false positives
+         * from `getSemanticDiagnostics`.
+         *
+         * While these represent the majority of syntax-related diagnostics, there are some
+         * that require the type system, which will be present in `getSemanticDiagnostics`.
+         *
+         * @param fileName A path to the file you want syntactic diagnostics for
+         */
         getSyntacticDiagnostics(fileName: string): DiagnosticWithLocation[];
-        /** The first time this is called, it will return global diagnostics (no location). */
+
+        /**
+         * Gets warnings or errors indicating type system issues in a given file.
+         * Requesting semantic diagnostics may start up the type system and
+         * run deferred work, so the first call may take longer than subsequent calls.
+         *
+         * Unlike the other get*Diagnostics functions, these diagnostics can potentially not
+         * include a reference to a source file. Specifically, the first time this is called,
+         * it will return global diagnostics with no associated location.
+         *
+         * To contrast the differences between semantic and syntactic diagnostics, consider the
+         * sentence: "The sun is green." is syntactically correct; those are real English words with
+         * correct sentence structure. However, it is semantically invalid, because it is not true.
+         *
+         * @param fileName A path to the file you want semantic diagnostics for
+         */
         getSemanticDiagnostics(fileName: string): Diagnostic[];
+
+        /**
+         * Gets suggestion diagnostics for a specific file. These diagnostics tend to
+         * proactively suggest refactors, as opposed to diagnostics that indicate
+         * potentially incorrect runtime behavior.
+         *
+         * @param fileName A path to the file you want semantic diagnostics for
+         */
         getSuggestionDiagnostics(fileName: string): DiagnosticWithLocation[];
 
         // TODO: Rename this to getProgramDiagnostics to better indicate that these are any
         // diagnostics present for the program level, and not just 'options' diagnostics.
-        getCompilerOptionsDiagnostics(): Diagnostic[];
 
         /**
-         * @deprecated Use getEncodedSyntacticClassifications instead.
+         * Gets global diagnostics related to the program configuration and compiler options.
          */
+        getCompilerOptionsDiagnostics(): Diagnostic[];
+
+        /** @deprecated Use getEncodedSyntacticClassifications instead. */
         getSyntacticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
 
-        /**
-         * @deprecated Use getEncodedSemanticClassifications instead.
-         */
+        /** @deprecated Use getEncodedSemanticClassifications instead. */
         getSemanticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
 
         // Encoded as triples of [start, length, ClassificationType].
         getEncodedSyntacticClassifications(fileName: string, span: TextSpan): Classifications;
         getEncodedSemanticClassifications(fileName: string, span: TextSpan): Classifications;
 
+        /**
+         * Gets completion entries at a particular position in a file.
+         *
+         * @param fileName The path to the file
+         * @param position A zero-based index of the character where you want the entries
+         * @param options An object describing how the request was triggered and what kinds
+         * of code actions can be returned with the completions.
+         */
         getCompletionsAtPosition(fileName: string, position: number, options: GetCompletionsAtPositionOptions | undefined): WithMetadata<CompletionInfo> | undefined;
-        // "options" and "source" are optional only for backwards-compatibility
+
+        /**
+         * Gets the extended details for a completion entry retrieved from `getCompletionsAtPosition`.
+         *
+         * @param fileName The path to the file
+         * @param position A zero based index of the character where you want the entries
+         * @param entryName The name from an existing completion which came from `getCompletionsAtPosition`
+         * @param formatOptions How should code samples in the completions be formatted, can be undefined for backwards compatibility
+         * @param source Source code for the current file, can be undefined for backwards compatibility
+         * @param preferences User settings, can be undefined for backwards compatibility
+         */
         getCompletionEntryDetails(
             fileName: string,
             position: number,
-            name: string,
+            entryName: string,
             formatOptions: FormatCodeOptions | FormatCodeSettings | undefined,
             source: string | undefined,
             preferences: UserPreferences | undefined,
         ): CompletionEntryDetails | undefined;
+
         getCompletionEntrySymbol(fileName: string, position: number, name: string, source: string | undefined): Symbol | undefined;
 
+        /**
+         * Gets semantic information about the identifier at a particular position in a
+         * file. Quick info is what you typically see when you hover in an editor.
+         *
+         * @param fileName The path to the file
+         * @param position A zero-based index of the character where you want the quick info
+         */
         getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined;
 
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): TextSpan | undefined;

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -5115,25 +5115,88 @@ declare namespace ts {
         metadata?: unknown;
     };
     interface LanguageService {
+        /** This is used as a part of restarting the language service. */
         cleanupSemanticCache(): void;
+        /**
+         * Gets errors indicating invalid syntax in a file.
+         *
+         * In English, "this cdeo have, erorrs" is syntactically invalid because it has typos,
+         * grammatical errors, and misplaced punctuation. Likewise, examples of syntax
+         * errors in TypeScript are missing parentheses in an `if` statement, mismatched
+         * curly braces, and using a reserved keyword as a variable name.
+         *
+         * These diagnostics are inexpensive to compute and don't require knowledge of
+         * other files. Note that a non-empty result increases the likelihood of false positives
+         * from `getSemanticDiagnostics`.
+         *
+         * While these represent the majority of syntax-related diagnostics, there are some
+         * that require the type system, which will be present in `getSemanticDiagnostics`.
+         *
+         * @param fileName A path to the file you want syntactic diagnostics for
+         */
         getSyntacticDiagnostics(fileName: string): DiagnosticWithLocation[];
-        /** The first time this is called, it will return global diagnostics (no location). */
+        /**
+         * Gets warnings or errors indicating type system issues in a given file.
+         * Requesting semantic diagnostics may start up the type system and
+         * run deferred work, so the first call may take longer than subsequent calls.
+         *
+         * Unlike the other get*Diagnostics functions, these diagnostics can potentially not
+         * include a reference to a source file. Specifically, the first time this is called,
+         * it will return global diagnostics with no associated location.
+         *
+         * To contrast the differences between semantic and syntactic diagnostics, consider the
+         * sentence: "The sun is green." is syntactically correct; those are real English words with
+         * correct sentence structure. However, it is semantically invalid, because it is not true.
+         *
+         * @param fileName A path to the file you want semantic diagnostics for
+         */
         getSemanticDiagnostics(fileName: string): Diagnostic[];
-        getSuggestionDiagnostics(fileName: string): DiagnosticWithLocation[];
-        getCompilerOptionsDiagnostics(): Diagnostic[];
         /**
-         * @deprecated Use getEncodedSyntacticClassifications instead.
+         * Gets suggestion diagnostics for a specific file. These diagnostics tend to
+         * proactively suggest refactors, as opposed to diagnostics that indicate
+         * potentially incorrect runtime behavior.
+         *
+         * @param fileName A path to the file you want semantic diagnostics for
          */
-        getSyntacticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
+        getSuggestionDiagnostics(fileName: string): DiagnosticWithLocation[];
         /**
-         * @deprecated Use getEncodedSemanticClassifications instead.
+         * Gets global diagnostics related to the program configuration and compiler options.
          */
+        getCompilerOptionsDiagnostics(): Diagnostic[];
+        /** @deprecated Use getEncodedSyntacticClassifications instead. */
+        getSyntacticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
+        /** @deprecated Use getEncodedSemanticClassifications instead. */
         getSemanticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
         getEncodedSyntacticClassifications(fileName: string, span: TextSpan): Classifications;
         getEncodedSemanticClassifications(fileName: string, span: TextSpan): Classifications;
+        /**
+         * Gets completion entries at a particular position in a file.
+         *
+         * @param fileName The path to the file
+         * @param position A zero-based index of the character where you want the entries
+         * @param options An object describing how the request was triggered and what kinds
+         * of code actions can be returned with the completions.
+         */
         getCompletionsAtPosition(fileName: string, position: number, options: GetCompletionsAtPositionOptions | undefined): WithMetadata<CompletionInfo> | undefined;
-        getCompletionEntryDetails(fileName: string, position: number, name: string, formatOptions: FormatCodeOptions | FormatCodeSettings | undefined, source: string | undefined, preferences: UserPreferences | undefined): CompletionEntryDetails | undefined;
+        /**
+         * Gets the extended details for a completion entry retrieved from `getCompletionsAtPosition`.
+         *
+         * @param fileName The path to the file
+         * @param position A zero based index of the character where you want the entries
+         * @param entryName The name from an existing completion which came from `getCompletionsAtPosition`
+         * @param formatOptions How should code samples in the completions be formatted, can be undefined for backwards compatibility
+         * @param source Source code for the current file, can be undefined for backwards compatibility
+         * @param preferences User settings, can be undefined for backwards compatibility
+         */
+        getCompletionEntryDetails(fileName: string, position: number, entryName: string, formatOptions: FormatCodeOptions | FormatCodeSettings | undefined, source: string | undefined, preferences: UserPreferences | undefined): CompletionEntryDetails | undefined;
         getCompletionEntrySymbol(fileName: string, position: number, name: string, source: string | undefined): Symbol | undefined;
+        /**
+         * Gets semantic information about the identifier at a particular position in a
+         * file. Quick info is what you typically see when you hover in an editor.
+         *
+         * @param fileName The path to the file
+         * @param position A zero-based index of the character where you want the quick info
+         */
         getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined;
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): TextSpan | undefined;
         getBreakpointStatementAtPosition(fileName: string, position: number): TextSpan | undefined;

tests/baselines/reference/api/typescript.d.ts

@@ -5115,25 +5115,88 @@ declare namespace ts {
         metadata?: unknown;
     };
     interface LanguageService {
+        /** This is used as a part of restarting the language service. */
         cleanupSemanticCache(): void;
+        /**
+         * Gets errors indicating invalid syntax in a file.
+         *
+         * In English, "this cdeo have, erorrs" is syntactically invalid because it has typos,
+         * grammatical errors, and misplaced punctuation. Likewise, examples of syntax
+         * errors in TypeScript are missing parentheses in an `if` statement, mismatched
+         * curly braces, and using a reserved keyword as a variable name.
+         *
+         * These diagnostics are inexpensive to compute and don't require knowledge of
+         * other files. Note that a non-empty result increases the likelihood of false positives
+         * from `getSemanticDiagnostics`.
+         *
+         * While these represent the majority of syntax-related diagnostics, there are some
+         * that require the type system, which will be present in `getSemanticDiagnostics`.
+         *
+         * @param fileName A path to the file you want syntactic diagnostics for
+         */
         getSyntacticDiagnostics(fileName: string): DiagnosticWithLocation[];
-        /** The first time this is called, it will return global diagnostics (no location). */
+        /**
+         * Gets warnings or errors indicating type system issues in a given file.
+         * Requesting semantic diagnostics may start up the type system and
+         * run deferred work, so the first call may take longer than subsequent calls.
+         *
+         * Unlike the other get*Diagnostics functions, these diagnostics can potentially not
+         * include a reference to a source file. Specifically, the first time this is called,
+         * it will return global diagnostics with no associated location.
+         *
+         * To contrast the differences between semantic and syntactic diagnostics, consider the
+         * sentence: "The sun is green." is syntactically correct; those are real English words with
+         * correct sentence structure. However, it is semantically invalid, because it is not true.
+         *
+         * @param fileName A path to the file you want semantic diagnostics for
+         */
         getSemanticDiagnostics(fileName: string): Diagnostic[];
-        getSuggestionDiagnostics(fileName: string): DiagnosticWithLocation[];
-        getCompilerOptionsDiagnostics(): Diagnostic[];
         /**
-         * @deprecated Use getEncodedSyntacticClassifications instead.
+         * Gets suggestion diagnostics for a specific file. These diagnostics tend to
+         * proactively suggest refactors, as opposed to diagnostics that indicate
+         * potentially incorrect runtime behavior.
+         *
+         * @param fileName A path to the file you want semantic diagnostics for
          */
-        getSyntacticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
+        getSuggestionDiagnostics(fileName: string): DiagnosticWithLocation[];
         /**
-         * @deprecated Use getEncodedSemanticClassifications instead.
+         * Gets global diagnostics related to the program configuration and compiler options.
          */
+        getCompilerOptionsDiagnostics(): Diagnostic[];
+        /** @deprecated Use getEncodedSyntacticClassifications instead. */
+        getSyntacticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
+        /** @deprecated Use getEncodedSemanticClassifications instead. */
         getSemanticClassifications(fileName: string, span: TextSpan): ClassifiedSpan[];
         getEncodedSyntacticClassifications(fileName: string, span: TextSpan): Classifications;
         getEncodedSemanticClassifications(fileName: string, span: TextSpan): Classifications;
+        /**
+         * Gets completion entries at a particular position in a file.
+         *
+         * @param fileName The path to the file
+         * @param position A zero-based index of the character where you want the entries
+         * @param options An object describing how the request was triggered and what kinds
+         * of code actions can be returned with the completions.
+         */
         getCompletionsAtPosition(fileName: string, position: number, options: GetCompletionsAtPositionOptions | undefined): WithMetadata<CompletionInfo> | undefined;
-        getCompletionEntryDetails(fileName: string, position: number, name: string, formatOptions: FormatCodeOptions | FormatCodeSettings | undefined, source: string | undefined, preferences: UserPreferences | undefined): CompletionEntryDetails | undefined;
+        /**
+         * Gets the extended details for a completion entry retrieved from `getCompletionsAtPosition`.
+         *
+         * @param fileName The path to the file
+         * @param position A zero based index of the character where you want the entries
+         * @param entryName The name from an existing completion which came from `getCompletionsAtPosition`
+         * @param formatOptions How should code samples in the completions be formatted, can be undefined for backwards compatibility
+         * @param source Source code for the current file, can be undefined for backwards compatibility
+         * @param preferences User settings, can be undefined for backwards compatibility
+         */
+        getCompletionEntryDetails(fileName: string, position: number, entryName: string, formatOptions: FormatCodeOptions | FormatCodeSettings | undefined, source: string | undefined, preferences: UserPreferences | undefined): CompletionEntryDetails | undefined;
         getCompletionEntrySymbol(fileName: string, position: number, name: string, source: string | undefined): Symbol | undefined;
+        /**
+         * Gets semantic information about the identifier at a particular position in a
+         * file. Quick info is what you typically see when you hover in an editor.
+         *
+         * @param fileName The path to the file
+         * @param position A zero-based index of the character where you want the quick info
+         */
         getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined;
         getNameOrDottedNameSpan(fileName: string, startPos: number, endPos: number): TextSpan | undefined;
         getBreakpointStatementAtPosition(fileName: string, position: number): TextSpan | undefined;